As the many testimonials in this book attest, stories involving Gabrielle Marceau are the opposite of ordinary. So is the one that led to this article. On a lucky rainy November morning, I received an e-mail from Gabrielle inviting me to deliver together a PhD course on treaty interpretation. I jumped on the opportunity to work with and learn from Gabrielle, and this took us on a year-long adventure. In the process of preparing for this course, I came to realize that the topic of treaty interpretation resembles the theory of everything. Both rely on a promise (rather than a reality) that, if ever fully understood, a theoretical framework would be able to explain and link together all aspects of a universe.<fnref n="2" /> Both are also unimaginably vast topics that lead researchers to the humbling philosophical conclusion of their own limitations (*I know that I know nothing*).

With this in mind, this article focuses on one relatively narrow aspect of the expansive universe of treaty interpretation—the method of identifying “the ordinary meaning to be given to the terms of the treaty”;<fnref n="3" /> and this from a relatively narrow perspective—the practice of trade and investment adjudicators.<fnref n="4" />

An immediate clarification should follow any choice of focusing on only one element of the *Vienna Convention on the Law of Treaties* (*VCLT*).<fnref n="5" /> As the International Law Commission (ILC) has explained, the application of the means of interpretation in Article 31 of the *VCLT* is “a single combined operation”, with all the various elements being “thrown into the crucible” and their interaction producing the “legally relevant interpretation.”<fnref n="6" /> If the underlying assumption is that the objective of the interpretative process is to ascertain the intention of the parties, it is only logical that the starting point of this process is determining the meaning of the words used by the parties. This is because

> the text must be presumed to be the authentic expression of the intentions of the parties; and […] in consequence, the starting point of interpretation is the elucidation of the meaning of the text, not an investigation *ab initio* into the intentions of the parties.<fnref n="7" />

Of course, the first impression as to the ordinary meaning of a term is nothing more than a starting point, as that ordinary meaning is immediately thrown into the crucible to be “intimately linked with context, and then to be taken in conjunction with all other relevant elements of the Vienna rules.”<fnref n="8" />

This article does not purport to delve into the very complex theoretical discussions on the concept, purpose and limits of interpretation, the role of the interpreter, the subtle borders between interpretation and application, or the relative importance of each element of the interpretative process. Instead, it focuses on a comparative analysis of the practice of adjudicators in the areas of international trade law and international investment law, with occasional comparisons to that of the International Court of Justice (ICJ), in an attempt to detect commonalities and differences. Section 1 briefly describes the adherence of each of these groups of adjudicators to the rules of interpretation set out in the *VCLT*, and examines the importance that each of these adjudicators attaches to the ordinary meaning of the terms of a treaty.<fnref n="9" /> Section 2 traces how these adjudicators have understood the concept of ordinary meaning. Section 3 focuses on where they have looked for the “ordinary meaning of the terms of the treaty.” Section 4 touches upon the question of the timing of the interpreters’ determination of ordinary meaning. Finally, Section 5 contrasts the concept of “ordinary meaning” to that of “special meaning” in their practice.

<footnote n="2">At the same time, this promise remains always elusive. As Andrea Bianchi and Fuad Zarbiyev, *Demystifying Treaty Interpretation* (Cambridge: Cambridge University Press, 2024) at ix aptly put it, “[t]o believe that the correct legal interpretation can be achieved by diligently applying the rules of treaty interpretation is tantamount to believing that Father Christmas, still domiciled at the North Pole, delivers the gifts you requested in a reindeer-drawn carriage floating in space and travelling at the speed of light.”</footnote>

<footnote n="3">*Vienna Convention on the Law of Treaties*, 23 May 1969, 1155 UNTS 331 art 31(1) (entered into force 28 January 1980) [*VCLT*].</footnote>

<footnote n="4">Throughout this article the term “adjudicators” is used in the context of WTO dispute settlement as shorthand for panels and the Appellate Body. Under the WTO rules, the role of these bodies is to assist the Members in the Dispute Settlement Body in making the recommendations or in giving the rulings provided for under the agreements.</footnote>

<footnote n="5">*VCLT*, *supra* note 3.</footnote>

<footnote n="6">“Draft Articles on the Law of Treaties with commentaries” (UN Doc A/CN.4/183) in *Yearbook of the International Law Commission 1966*, vol 2 (New York: UN, 1967) at 219—20 [“Draft Articles”]; the arbitral tribunal in *Aguas del Tunari v Bolivia* (2005), Case No ARB/02/3 at para 91 (International Centre for Settlement of Investment Disputes) described interpretation under Article 31 of the *VCLT* as “a process of progressive encirclement where the interpreter starts under the general rule with (1) the ordinary meaning of the terms of the treaty, (2) in their context and (3) in light of the treaty’s object and purpose, and by cycling through this three step inquiry iteratively closes in upon the proper interpretation” [*Aguas del Tunari*].</footnote>

<footnote n="7">“Draft Articles”, *supra* note 6 at para 11; as Jeremy Hill, *Aust*’*s Modern Treaty Law and Practice*, 4th ed (Cambridge: Cambridge University Press, 2023) at 243 puts it, “it is reasonable to assume, at least until the contrary is established, that the ordinary meaning is most likely to reflect what the parties intended.”</footnote>

<footnote n="8">Richard Gardiner, *Treaty Interpretation*, 2nd ed (Oxford: Oxford University Press, 2016) at 181.</footnote>

<footnote n="9">An emphatic criticism of the *VCLT*’s focus on the text of the treaty came from the New Haven School, characterized by a policy-oriented approach to jurisprudence. According to Professor Myres McDougal, “The International Law Commission’s Draft Articles upon Interpretation: Textuality Redivivus” (1967) 61:4 AJIL 992 at 992: “[t]he great defect, and tragedy, in the International Law Commission’s final recommendations about the interpretation of treaties is in their insistent emphasis upon an impossible, conformity-imposing textuality.”</footnote>
# I. The Mantra of Ordinary Meaning

In the process of drafting the *VCLT*, the ILC was unanimous that the starting point of treaty interpretation is “the meaning of the text.”<fnref n="10" /> This may appear nowadays dictated by logic, to the extent that a treaty is a written text, and the words in that text are the logical, maybe the only, tool allowing the interpreter to ascertain the intention of the parties to the treaty. Nevertheless, the focus on ordinary meaning was also based on the consistent practice of international adjudicators, most notably the Permanent Court of International Justice (PCIJ). In its advisory opinion on the *Polish Postal Service in Danzig*, the PCIJ reproduced several articles of the *Agreement of Warsaw*<fnref n="11" /> between Poland and the Free City of Danzig, and then unequivocally stated that “the postal service which Poland is entitled to establish in the port of Danzig must be interpreted in its ordinary sense so as to include the normal functions of a postal service as regards the collection and distribution of postal matter outside the post-office.”<fnref n="12" /> Since then, “the principle of ordinary meaning has become well established as a fundamental guide to interpreting treaties.”<fnref n="13" /> The ICJ was even more unequivocal in one of its first advisory opinions, on the Competence of the General Assembly for the Admission of a State to the United Nations, by stating that:

> the first duty of a tribunal which is called upon to interpret and apply the provisions of a treaty, is to endeavour to give effect to them in their natural and ordinary meaning in the context in which they occur. If the relevant words in their natural and ordinary meaning make sense in their context, that is an end of the matter.<fnref n="14" />

It then clearly formulated what this article refers to as the “mantra of ordinary meaning” in its judgment on the *Territorial Dispute between Libya and Chad*: “[i]nterpretation must be based above all upon the text of the treaty.”<fnref n="15" />

Even before the establishment of the World Trade Organization (WTO), *GATT* adjudicators referred to the “normal meaning of words” as the starting point of the interpretative process.<fnref n="16" /> With the express reference in Article 3.2 of the *Understanding on Rules and Procedures Governing the Settlement of Disputes* (*DSU*)<fnref n="17" /> to the “customary rules of interpretation of public international law”, using the rules of interpretation codified in the *VCLT* became axiomatic for WTO adjudicators.<fnref n="18" /> In its first report, the Appellate Body not only posited that the “general rule of interpretation” set out in Article 31(1) of the *VCLT* forms part of the customary rules referred to in Article 3.2 of the *DSU*. It also specifically focused the interpretative process on the meaning of words, criticizing the panel for failing to “take adequate account of the words actually used” in the relevant provision.<fnref n="19" /> The Appellate Body in a subsequent case stressed that “the words of the treaty form the foundation for the interpretative process”, specifically quoting the ICJ judgment on the *Territorial Dispute between Libya and Chad*.<fnref n="20" /> Ever since, WTO adjudicators have continuously considered that the task of interpreting a treaty provision must begin with its specific terms, and the duty of an interpreter is to examine the words of the treaty to determine the intention of the parties.<fnref n="21" /> In the words of the former Appellate Body Member Georges Abi-Saab, the practice of WTO panels and the Appellate Body reflects “a great emphasis on words, even individual words, greater than in any other international forum, which verges on obsession.”<fnref n="22" />

Investment arbitrators have also traditionally used what the tribunal in *AAPL v Sri Lanka*described as “the sound universally accepted rules of treaty interpretation as established in practice, […] as codified in Article 31 of the Vienna Convention on the Law of Treaties.”<fnref n="23" /> Reliance on the *VCLT* is of particular importance in the context of investment arbitration. As Thomas W Wälde explains, the rules of interpretation in the *VCLT* have become “popular” among investment tribunals not only because they “very much need and seek an authoritative anchor—and preferably a generally recognized international one—to enhance the legitimacy of their operation”, but also because these rules constitute

> a well-formulated compromise between the major legal traditions; the more literal approach of the English legal (and international law) tradition and the more teleological interpretation tradition, focused on identifying the ‘common meaning’ and ‘policy’ of the parties in civil law countries (but also the US).<fnref n="24" />

While arbitral tribunals also appear to have adhered to the mantra of ordinary meaning,<fnref n="25" /> any generalisation should be carefully situated against the specific backdrop of investment arbitration: a multiplicity of treaties using different (or identical) words to define key terms (such as “investment” or “investor”) and to set key standards of treatment. For interpreters, this implies “a constant hesitation between referring to general concepts, whose meaning is more or less clearly established in the field, and focusing on the specific drafting of each treaty.”<fnref n="26" />

<footnote n="10">“Draft Articles”, *supra* note 6 at para 9.</footnote>

<footnote n="11">*Agreement for the purpose of executing and completing the Polish-Danzig Convention of November 9, 1920*, 24 October 1921, 116 UNTS 5.</footnote>

<footnote n="12">*Polish Postal Service in Danzig* (1925), PCIJ (Ser B) No 11 at 104.</footnote>

<footnote n="13">James Crawford, *Brownlie’s Principles of Public International Law*, 9th ed (Oxford: Oxford University Press, 2019) at 367.</footnote>

<footnote n="14">*Competence of the General Assembly for the Admission of a State to the United Nations*, Advisory Opinion, [1950] ICJ Rep 4 at 8.</footnote>

<footnote n="15">*Territorial Dispute (Libyan Arab Jamahiriya/Chad)*, [1994] ICJ Rep 6 at para 41.</footnote>

<footnote n="16">*Panel on Import*,*Distribution and Sale of Alcoholic Drinks by Provincial Marketing Authorities* (1988), GATT Doc L/6304, 35th Supp BISD (1988—89) 37 at para 4.16, online: <wto.org> [perma.cc/4UPN-QKQT]: “[t]he Panel considered that the phrase ‘a reasonable margin of profit’ should be interpreted in accordance with the normal meaning of these words in their context of Article II [of the *GATT*] and Article 31 of the Havana Charter.”</footnote>

<footnote n="17">*Understanding on Rules and Procedures Governing the Settlement of Disputes*, 15 April 1994, 1869 UNTS 401, Annex 2 of the *Marrakesh Agreement Establishing the World Trade Organization*, 15 April 1994, 1867 UNTS 154 [*Marrakesh Agreement*].</footnote>

<footnote n="18">As the Appellate Body observed *United States—Anti-Dumping Measures on Certain Hot-Rolled Steel Products from Japan* (2001), WTO Doc WT/DS184/AB/R at para 60 (Appellate Body Report), online: <wto.org> [perma.cc/VF9X-KEUB]: “[t]he rules of treaty interpretation in Articles 31 and 32 of the *Vienna Convention* apply to any treaty, in *any* field of public international law, and not just to the WTO agreements. These rules of treaty interpretation impose certain common disciplines upon treaty interpreters, irrespective of the content of the treaty provision being examined and irrespective of the field of international law concerned.”</footnote>

<footnote n="19">*United States—Standards for Reformulated and Conventional Gasoline* (1996), WTO Doc WT/DS2/AB/R at 17 (Appellate Body Report), online: <wto.org> [perma.cc/2KVT-XRSJ].</footnote>

<footnote n="20">*Japan—Taxes on Alcoholic Beverages* (1996), WTO Doc WT/DS 8, 10, 11/AB/R at 11 (Appellate Body Report), online: <wto.org> [perma.cc/D47P-TXGA].</footnote>

<footnote n="21">See *United States—Countervailing Duties on Certain Corrosion-Resistant Carbon Steel Flat Products from Germany* (2002), WTO Doc WT/DS213/AB/R at para 62 (Appellate Body Report), online: <wto.org> [perma.cc/Y225-WQZS]; *India—Patent Protection for Pharmaceutical and Agricultural Chemical Products* (1997), WTO Doc WT/DS50/AB/R at para 45 (Appellate Body Report), online: <wto.org> [perma.cc/N3KP-262W].</footnote>

<footnote n="22">Georges Abi-Saab, “The Appellate Body and Treaty Interpretation” in Malgosia Fitzmaurice, Olufemi Elias & Panos Merkouris, eds, *Treaty Interpretation and the Vienna Convention on the Law of Treaties: 30 Years on* (Leiden: Martinus Nijhoff, 2010) 99 at 106.</footnote>

<footnote n="23">*Asian Agricultural Products Ltd v Republic of Sri Lanka* (1990), Case No ARB/87/3 at para 38 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="24">Thomas W Wälde, “Interpreting Investment Treaties: experiences and examples” in Christina Binder et al, eds, *International Investment Law for the 21st Century: Essays in Honour of Christoph Schreuer* (Oxford: Oxford University Press, 2009) 724 at 746.</footnote>

<footnote n="25">See e.g. *Wintershall Aktiengesellschaft v Argentine Republic* (2008), Case No ARB/04/14 at para 77 (International Centre for Settlement of Investment Disputes); or *Siemens AG v The Argentine Republic* (2007), Case No ARB/02/8 at paras 80, 290 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="26">Hervé Ascensio, “Article 31 of the Vienna Conventions on the Law of Treaties and International Investment Law” (2016) 31:2 ICSID Rev 366 at 367.</footnote>
# II. Theoretical Inception: What is “Ordinary Meaning”?

## A. Interpreting the Terms “Ordinary Meaning”

To the extent that the *VCLT* is an international treaty, it is only logical that the customary rules of interpretation of public international law codified in its Article 31(1) apply equally for the interpretation of its own provisions. As a result, the starting point of interpreting Article 31(1) of the *VCLT* is the determination of the ordinary meaning to be given to the terms “ordinary meaning” in their context and in the light of the object and purpose of the *VCLT*.

The *Oxford English Dictionary* defines “ordinary” as “belonging to the regular or usual order or course of things […] normal; customary; usual”, and “meaning” as “the sense or signification of a word, sentence, etc.”<fnref n="27" /> The dictionary meaning of both these terms is vague at best.<fnref n="28" /> In that vein, the investment tribunal in *Aguas del Tunari v Bolivia* quoted an observation by Professor Schwarzenberger that “the word ‘meaning’ itself has at least sixteen dictionary meanings.”<fnref n="29" />

The vagueness is not dispersed by the immediate context of “ordinary meaning” in Article 31(1), which is composed of the words “to be given to the terms of the treaty.”<fnref n="30" /> The *Oxford English Dictionary* defines “term” as “a word or phrase used in a precise sense in a particular subject or field, or by a particular group of people”, but also as “a condition under which something may be done, settled, agreed, or granted; a stipulated requirement or limitation.”<fnref n="31" /> In the context of the negotiation of the *VCLT*, Special Rapporteur Humphrey Waldock explained that the word “term”, as ambiguous as it may appear, was chosen (probably precisely because of its ambiguity), to the extent that it combines a linguistic sense and the legal sense of “provision.” According to the Special Rapporteur, “the two senses are concordant and the rule is meaningful and valid for both.”<fnref n="32" /> The choice of the words “to be given”, instead of a simpler formulation (“the ordinary meaning of the terms”), is also not accidental. It adds an aspect of subjectivity to the interpretative process and emphasizes that the meaning is not inherent in the text but, as Richard Gardiner observes, “something to be attributed by the interpreter, albeit using the text in the manner required by the rules.”<fnref n="33" />

Zooming out on the context of “ordinary meaning”, the remaining part of Article 31(1) refers to “the context” of the terms of the treaty, its “object and purpose”, and the general dictum of interpreting treaties “in good faith.”<fnref n="34" /> This context suggests that, for the purposes of the interpretative process, tracing the contours of the “ordinary meaning” of a term is the first step before this meaning gets immediately contextualized. The ILC was adamant that “the ordinary meaning of a term is not to be determined in the abstract.”<fnref n="35" /> Rather, the meaning of the terms should be concretized, which means that it is “determined as a function of the context, object and purpose of the treaty.”<fnref n="36" /> Pushing this logic a step further, in its advisory opinion on the *Constitution of the Maritime Safety Committee of the Inter-Governmental Maritime Consultative Organization*, the ICJ seems to even doubt the idea that an ordinary meaning exists before it is contextualized. According to the Court, “[t]he word obtains its meaning from the context in which it is used. If the context requires a meaning which connotes a wide choice, it must be construed accordingly, just as it must be given a restrictive meaning if the context in which it is used so requires.”<fnref n="37" />

This approach to “ordinary meaning” as a necessary but insufficient step towards determining the meaning of the terms of a treaty transpires in the interpretative process followed by trade and investment adjudicators. With respect to trade adjudicators, the panel in *US—Section 301 Act* considered that

> [f]or pragmatic reasons the normal usage, and we will follow this usage, is to start the interpretation from the ordinary meaning of the “raw” text of the relevant treaty provisions and then seek to construe it in its context and in the light of the treaty’s object and purpose.<fnref n="38" />

Isabelle Van Damme observes that the WTO Appellate Body also often immediately contextualized dictionary definitions or the plain meaning of the text and used the contextualized ordinary meaning as the keystone upon which the interpretation is built.<fnref n="39" />

With respect to investment adjudicators, the arbitral tribunal in *Methanex v USA* also appears to have formulated a version of the general idea that “ordinary meaning” cannot exist in the abstract. When interpreting the phrase “relating to” in Article 1101(1) of the *North American Free Trade Agreement* (*NAFTA*),<fnref n="40" /> the tribunal refused to decide the issue on a purely semantic basis, emphasizing that “there is a difference between a literal meaning and the ordinary meaning of a legal phrase.”<fnref n="41" />

If the interpretation of the terms “ordinary meaning” used in Article 31(1) of the *VCLT* leads to the conclusion that the ordinary meaning of terms is interwoven with their context and the object and purpose of the treaty, the question may be asked whether the words used in the treaty even matter. For example, would it have made any difference if the *VCLT* used the word “natural” or “plain” rather than “ordinary”, when—either way—the interpreter would have determined the meaning of the phrase by reference to its context and the object and purpose of the *VCLT*? To the mind of the author, the answer to this question is always yes—words matter. This is because the only way in which the context and the object and purpose can be distilled is through the words used to express them, i.e. the words surrounding the interpreted terms.

In that sense, the words used in a treaty are the anchor that stabilizes the interpretative process. There appear to be at least two reasons why interpretation is and needs to be anchored to words. First, the words used in a treaty are the only available tool to access the parties’ intention.<fnref n="42" /> Second, words can be perceived as an objective factor, or at least the most objective one that exists. Consequently, relying on them is, and even more importantly—appears to be, less subjective than any alternative.<fnref n="43" /> In that sense, Andrea Bianchi and Fuad Zarbiyev note the constant concern of international lawyers to “place international law upon solid foundations that are incapable of being manipulated”, and the many examples in classic international law literature designed to show why ordinary meaning is “an indispensable device to avoid perfidy.”<fnref n="44" />

## B. The Meaning and Meanings of Terms

The proposition that words are objective is controversial. This is because, as much as they are the anchor of the interpretative process, the words used in treaties are not necessarily clear.<fnref n="45" /> Interpretation is certainly an act of cognition, i.e. “the very process of grasping or apprehending the sense of a word, a sentence, or a normative proposition, of identifying and delimiting its substance.”<fnref n="46" /> However, it is also an act of volition, to the extent that it involves choosing between alternative possible meanings as an exercise of free will and conscious decision.<fnref n="47" /> But then again, the extent of subjectivity is constrained by the words used: there is a limited number of alternative interpretations available to even the most creative interpreter, and they are circumscribed by the term to be interpreted.<fnref n="48" />

A good illustration of the inevitable but limited subjectivity of determining the “ordinary meaning” of a term is the choice made by adjudicators between the different meanings of a word listed in a dictionary. This choice is necessarily informed by the specific context of the term in the treaty and the relevant professional discourse.<fnref n="49" /> The WTO Appellate Body was particularly clear on its approach when it noted that

> very few—if any—words have only one dictionary meaning. Thus, even the step of choosing the relevant dictionary meaning(s) in pursuit of “ordinary meaning”—often the very first step in treaty interpretation—necessarily involves a reference to the context in which the word is used. Referring to the object and purpose of an agreement may also be indispensable to arriving at the meaning of a word.<fnref n="50" />

The relevance of the context of the interpreted term and of the object and purpose of the treaty in that process does not necessarily mean that there is more than one “ordinary meaning” of a term.<fnref n="51" /> Rather, it confirms the ILC’s statement that the “ordinary meaning” of a term fluctuates and cannot be determined in the abstract: it will vary depending on the other elements of the interpretative process.

The terms used in a treaty do not only exist in one another’s context, and in the broader space of the treaty’s object and purpose. They also coexist in grammatical structures, the analysis of which cannot be ignored when determining their meaning. “Ordinary meaning” consists also of immediate indicators of meaning such as grammar and syntax, which can be considered part of the text itself.<fnref n="52" /> WTO adjudicators have thus considered the grammatical construction of provisions in their interpretative process on more than one occasion,<fnref n="53" /> with one panel even noting that the grammatical structure of a sentence is “part of the ordinary meaning of the relevant treaty terms” and adding that neither party to the dispute had questioned this.

<footnote n="27">Oxford English Dictionary, sub verbo “Ordinary”, online: <oed.com> [perma.cc/J42U-8A6W]; Oxford English Dictionary, sub verbo “Meaning”, online: <oed.com> [perma.cc/L9CG-T4CL]; the use of dictionaries here is proof of the limited availability of reference points for determining the ordinary meaning of terms, and is admittedly somewhat ironic in the light of the developments in Section 3 below.</footnote>

<footnote n="28">According to Jeffrey Stout, “What is the Meaning of a Text?” (1982) 14:1 New Literary History 1 at 2 if “considerable […] disagreement has grown up around the topic of meaning, that must be because the term itself is ambiguous.”</footnote>

<footnote n="29">*Aguas del Tunari*, *supra* note 6 at para 91.</footnote>

<footnote n="30">The term “treaty” is expressly defined in the *VCLT*, *supra* note 4, art 1 as “an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation.”</footnote>

<footnote n="31">Oxford English Dictionary, sub verbo “Term”, online: <oed.com> [perma.cc/5VQE-SZ4R].</footnote>

<footnote n="32">“Draft Articles”, *supra* note 6 at para 8.</footnote>

<footnote n="33">Gardiner, *supra* note 8 at 184.</footnote>

<footnote n="34">*VCLT*, *supra* note 3, art 31(1).</footnote>

<footnote n="35">“Draft Articles”, *supra* note 6 at para 12.</footnote>

<footnote n="36">*Case concerning the audit of accounts between the Netherlands and France in application of the Protocol of 25 September 1991 Additional to the Convention for the Protection of the Rhine from Pollution by Chlorides of 3 December 1976* (2004), PCA (Permanent Court of Arbitration) at para 63; according to Lord McNair, *The Law of Treaties*(Oxford: Oxford University Press, 1986) at 36*7*: “while a term may be ‘plain’ *absolutely*, what a tribunal adjudicating upon the meaning of a treaty wants to ascertain is the meaning of the term *relatively*, that is, in relation to the circumstances in which the treaty was made, and in which the language was used.”</footnote>

<footnote n="37">*Constitution of the Maritime Safety Committee of the Inter-Governmental Maritime Consultative Organizatio*n, Advisory Opinion, [1960] ICJ Rep 150 at 158.</footnote>

<footnote n="38">*United States—Sections 301—310 of the Trade Act of 1974* (1999), WTO Doc WT/DS152/R at para 7.22 (Panel Report), online: <wto.org> [perma.cc/W7F7-QQGR].</footnote>

<footnote n="39">Isabelle Van Damme, “Treaty Interpretation by the WTO Appellate Body” (2010) 21:3 Eur J Intl L 605 at 621—35.</footnote>

<footnote n="40">*North American Free Trade Agreement*, 17 December 1992, Can TS 1994 No 2 art 1101(1) (Canada, Mexico, and US) (entered into force 1 January 1994) [*NAFTA*].</footnote>

<footnote n="41">*Methanex Corporation v United States of America* (2002), UNCITRAL at para 136 (United Nations Commission on International Trade Law) [*Methanex*].</footnote>

<footnote n="42">As Clément Marquet, “Prospective Linguistics and Trade: The Art of the Deal” in Georges Abi-Saab et al, eds, *Evolutionary Interpretation and International Law* (Oxford: Hart Publishing, 2019) 195 at 197 points out, “while intention remains the core of the reasoning, it is accessed through a proxy: the actual vocabulary used.”</footnote>

<footnote n="43">Or, as Wälde, *supra* note 26 at 752—53, puts it, than “struggling through the possible impact of a particular interpretation forecast for an uncertain future by a tribunal or counsel with no expertise in or mandate for economic planning and social engineering.”</footnote>

<footnote n="44">Bianchi & Zarbiyev, *supra* note 2 at 87.</footnote>

<footnote n="45">McNair, *supra* note 36 at 367—68 speaks of “[t]he *relative* character of words, that is, their meaning in relation to the persons using them and the circumstances in which they are used.”</footnote>

<footnote n="46">Georges Abi-Saab, “Introduction: a Meta-Question” in Georges Abi-Saab et al, *supra* note 42, 7 at 7.</footnote>

<footnote n="47">*Ibid* at 8; or, as Eirik Bjorge, “Time Present and Time Past: The Intention of the Parties and the Evolutionary Interpretation of Treaties” in Georges Abi-Saab et al, *supra* note 42, 35 at 36 puts it, “interpretation, even of seemingly clear words in the treaty, on the basis of an objective means of interpretation, and in pursuit of an objectivized intention of the parties, will be a subjective undertaking because rational minds can and will disagree on the correct interpretation.”</footnote>

<footnote n="48">According to Umberto Eco, *The Limits of Interpretation* (Bloomington: Indiana University Press, 1990) at 5—6, the “literal meaning of lexical items”, i.e. the one listed first by dictionaries as well as the one that “Everyman would first define when requested to say what a given word means” creates constraints, that “[n]o reader-oriented theory can avoid […]. Any act of freedom on the part of the reader can come *after*, not *before*, the acceptance of that constraint.”</footnote>

<footnote n="49">Wälde, *supra* note 24 at 753.</footnote>

<footnote n="50">*Canada—Certain Measures Affecting the Automotive Industry* (2000), WTO Doc WT/DS139, 142/AB/R at 356, n 807 (Appellate Body Report), online: <wto.org> [perma.cc/N3U3-BWD3].</footnote>

<footnote n="51">Dongsheng Zang, “Textualism in GATT/WTO Jurisprudence: Lessons for the Constitutionalization Debate” (2006) 33:2 Syracuse J Intl L & Com 393 at 429 argues that “the trouble with textualism is that it can be easily paralyzed by the fact that there are always more than one ordinary meaning.”</footnote>

<footnote n="52">Isabelle Van Damme, *Treaty Interpretation by the WTO Appellate Body* (Oxford: Oxford University Press, 2009) at 234.</footnote>

<footnote n="53">*China—Measures Affecting Imports of Automobile Parts* (2008), WTO Doc WT/DS339, 340, 342/R at para 7.163 (Panel Report), online: <wto.org> [perma.cc/ZC8P-F4S4]; *European Communities and Certain Member States—Measures Affecting Trade in Large Civil Aircraft* (2010), WTO Doc WT/DS316/R at para 7.218 (Panel Report), online: <wto.org> [perma.cc/DGH3-V8XE]; *Australia—Certain Measures Concerning Trademarks*,*Geographical Indications and Other Plain Packaging Requirements Applicable to Tobacco Products and Packaging* (2018), WTO Doc WT/DS435, 441, 458, 467/R at para 7.1892 (Panel Report), online: <wto.org> [perma.cc/2P85-QF3Z].</footnote>
# III. Where to Find “Ordinary Meaning”?

With all of the above caveats in mind, the determination of “ordinary meaning” still needs to start somewhere. While the ICJ has rarely been particularly explicit about its methodology,<fnref n="54" /> trade adjudicators, and to a certain extent investment arbitrators, have traditionally considered dictionaries as a useful starting point for establishing the ordinary meaning of terms.

Comparatively, the most extensive use of dictionaries can be detected in the practice of trade adjudicators. Panels and the Appellate Body routinely refer to dictionaries when interpreting the terms in the WTO agreements.<fnref n="55" /> Their preference appears to be, at least with respect to the English version of the agreements, for the *Shorter Oxford English Dictionary* (more recently, the Oxford English Dictionary online), and—where relevant—for specialized dictionaries (mostly legal, such as *Black’s Law Dictionary<fnref n="56" />* and the *Meriam-Webster’s Dictionary of Law*,<fnref n="57" /> but occasionally also technical dictionaries).<fnref n="58" />

The choice between different general dictionaries may appear somewhat arbitrary, but could possibly be explained by a quest of consistency and by the adjudicators’ satisfaction with the lexical choices offered by the *Oxford English Dictionary*.<fnref n="59" /> Where panels or the Appellate Body have used more than one dictionary to compare the proposed definitions, they have concluded that “all or most dictionary meanings were illustrative of the meaning of the treaty language and affirmed each other or the common understanding about a certain term or phrase.”<fnref n="60" /> Where this is not the case, however, the choice of consulting one or more dictionaries matters. In *US—Gambling*, the panel surveyed thirteen different definitions of “sporting”, offered by a number of dictionaries to reach the conclusion that the ordinary meaning of “sporting” does not include gambling.<fnref n="61" /> The large array of available definitions here, however, proved to broaden rather than narrow the interpretative process. The Appellate Body criticized the panel for failing to have due regard to the fact that its recourse to dictionaries revealed that gambling and betting can, at least in some contexts, be one of the meanings of the word “sporting.”<fnref n="62" />

The choice between a general and a specialized dictionary could also be consequential. For instance, the panel in *Thailand—H-Beams* relied on the *Concise Oxford Dictionary* to determine the ordinary meaning of the term “positive evidence” in Article 3.1 of the *Anti-dumping Agreement*.<fnref n="63" /> In its appeal, Thailand argued that this had distorted the panel’s analysis of the meaning of the term “positive evidence” as used in the specific context of that *Agreement*, and that the panel should have instead relied on the definition found in *Black’s Law Dictionary*.<fnref n="64" /> The Appellate Body avoided entering into a debate about the choice of dictionaries, focusing rather on what the ordinary meaning of these terms (even if one were to accept that it is reflected in the dictionary definitions cited by the panel) suggests.<fnref n="65" />

The reliance by trade adjudicators on dictionary definitions has not remained without criticism. Joseph Weiler and Henrik Horn criticize the Appellate Body’s “often obsessive use of dictionaries.”<fnref n="66" /> William Davey reports that

> the Appellate Body’s particular focus on individual words and very extensive use of dictionary meanings was new and caused some to joke that The *New Oxford Shorter English Dictionary*—the Appellate Body’s favourite dictionary—had become a ‘covered agreement’ under the *DSU*.<fnref n="67" />

Dongsheng Zang even notes that, on some occasions, WTO adjudicators have directly referred to “dictionary meaning” when they actually meant “ordinary meaning.”<fnref n="68" /> On the other hand, the Appellate Body has also occasionally insisted precisely on the difference between the two. In *US—Gambling*, it criticized the panel’s reasoning to the extent that it had simply equated “ordinary meaning” with the meaning of words as defined in dictionaries. In the view of the Appellate Body, this was “too mechanical an approach.”<fnref n="69" />

Investment arbitrators appear somewhat more reserved than trade adjudicators when it comes to acknowledging the usefulness of dictionary definitions, although they have also consulted dictionaries as the starting point of the interpretative process. For instance, in *ADF v United States*, the tribunal started its analysis of the ordinary meaning of the term “procurement” in Article 1101(5) of *NAFTA* by consulting the definitions of “procurement” and “procure” in *Webster’s New Twentieth Century Dictionary of the English Language*.<fnref n="70" /> Investment tribunals have also not shied away from general dictionaries as a starting point for their interpretation of highly specialized terms, such as “enterprise”, “asset”,<fnref n="71" /> or even “fair and equitable treatment.”<fnref n="72" /> Interestingly, in its Decision on Annulment, the ICSID *ad hoc* Committee in *Tulip Real Estate v Turkey* used the *Oxford English Dictionary* to interpret the term “remit” used not in the relevant investment treaty, but in the investment tribunal’s statement that the conduct of a Turkish real estate investment trust was “outside of the remit” of the tribunal. On the basis of this dictionary definition, the *ad hoc* Committee considered that the tribunal had meant “competence” or “jurisdiction” when using the term “remit.”<fnref n="73" />

The ICJ has also occasionally used dictionaries to find the ordinary meaning of certain terms.<fnref n="74" /> For instance, called upon to interpret the term “commerce” in Article X, paragraph 1 of the *Treaty of Amity*,*Economic Relations and Consular Rights between the United States of America and Iran*<fnref n="75" /> in the *Oil Platforms case*, it relied on a series of dictionary definitions relating to progressively narrower fields, which all appeared to lead to the same conclusion—that the term has a broader meaning than the mere reference to purchase and sale. The Court’s analysis of the ordinary meaning of “commerce” started from a relatively broad definition found in the *Oxford English Dictionary*, zoomed in to the definition found in a specialized dictionary of “legal language” (*Black’s Law Dictionary*), and then further focused on the definition of the expression “international commerce”, for which—curiously—the Court used the French-language *Dictionnaire de la terminologie du droit international* (in a translation by the Registry) to interpret the term in the English version of the treaty.<fnref n="76" /> Against this backdrop, Vice-President Schwebel’s Dissenting Opinion provides a serendipitous example of the subjectivity inherent to the choice of dictionary definitions. The ICJ’s interpretation had led it to the conclusion that the word “commerce” in the treaty covered commercial activities in general, including “ancillary activities integrally related to commerce.”<fnref n="77" /> Vice-President Schwebel took issue with the ensuing consequence that “commerce” included also “production.” Using the same dictionary definitions as the ones quoted by the Court, and adding thereto a “dozen or more dictionaries in the Library of the Court”, Vice-President Schwebel observed that there is no definition that includes production as part of commerce.<fnref n="78" />

All things considered, while dictionary definitions may appear to offer a solid foundation for discovering the ordinary meaning of words, they suffer from two shortcomings that limit their usefulness in the interpretative process. First, there are as many dictionaries, and dictionary definitions, as the interpreter finds and continues to search for. Second, even the most specialized dictionaries can only provide abstract definitions which—unless contextualized—would only fit imperfectly in the interpretative puzzle. As Andrea Bianchi and Fuad Zarbiyev explain,

> [w]e never grasp the ordinary meaning of a term on the basis of its linguistic features. Any decent dictionary would list more than one “ordinary meaning” for most words, but no dictionary could tell us which of those meanings is the ordinary meaning for the purpose of a particular treaty provision for the simple reason that “a dictionary is a statistical report, an historical record of the intentional uses to which words have been put in the past, not a normative one.”<fnref n="79" />

This may explain why trade and investment adjudicators, as well as the ICJ, have cautioned against overreliance on dictionaries. The WTO Appellate Body has considered dictionary definitions to be important guides to, but “not dispositive statements of, definitions of words appearing in agreements and legal documents”,<fnref n="80" /> mostly because they “have their limitations in revealing the ordinary meaning of a term”,<fnref n="81" /> they are “not necessarily capable of resolving complex questions of interpretation, as they typically aim to catalogue *all* meanings of words—be those meanings common or rare, universal or specialized”,<fnref n="82" /> and “leave many interpretative questions open.”<fnref n="83" /> For trade adjudicators, dictionaries are only a useful starting point of the analysis, to the extent that “the first step is to find ‘a’ and not necessarily ‘the’ meaning of the text.”<fnref n="84" />

In a similar vein, the investment tribunal in *Methanex v US* noted that two “rival interpretations” of the phrase “relating to”, for both of which the parties relied extensively on dictionary definitions, could be advanced in good faith. As a result, for the tribunal none of the available dictionary definitions was determinative. The tribunal was particularly didactic in explaining that the issue before it could not be decided “on a purely semantic basis.”<fnref n="85" />

The ICJ has also noted the inherent limitations of recourse to dictionaries to determine the ordinary meaning of terms. In the *Aegean Sea Continental Shelf case*, the Court examined the meaning of the words “*et*,*notamment*” contained in Greece’s instrument of accession to the *General Act for the Pacific Settlement of International Disputes*<fnref n="86" /> of 1928. The ICJ noted that the dictionary meaning suggested by one of the parties was “not the only, although it may be the most frequent, use of that expression.”<fnref n="87" /> Finding no further details in dictionaries, the Court concluded that the interpretation of “*et*,*notamment*” depended on the context in which those words were used in Greece’s instrument of accession and was “not a matter simply of their preponderant linguistic usage.”<fnref n="88" /> The ICJ’s dissatisfaction with the limitations of dictionaries was much less veiled in *Avena* where it had to interpret the term “without delay” contained in Article 36, paragraph 1 of the *Vienna Convention on Consular Relations*.<fnref n="89" /> The Court merely observed that dictionary definitions, in the various languages of the *Vienna Convention*, offered diverse meanings of the term, and that it was therefore necessary to “look elsewhere for an understanding of this term.”<fnref n="90" />

In sum, trade and investment adjudicators, as well as the ICJ, appear to be simultaneously somewhat enthusiastic about and disappointed by dictionary definitions as the source of “ordinary meaning.” This limited utility of dictionaries in the interpretative process can be explained by the incongruity between what dictionaries can offer and what the adjudicators-interpreters need from them. Umberto Eco describes two semantic models competing to explain how human beings produce and understand texts: the “dictionary model”, according to which “a language is a series of items explained by a concise definition, usually composed by a finite set of semantic universals, that cannot be further analyzed”, and the “encyclopaedia model”, which is “based on the assumption that every item of a language must be interpreted by every other possible linguistic item which, according to some previous cultural conventions, can be associated with it.”<fnref n="91" /> While a dictionary defines words by reference to other words and thus a dictionary-like representation concerns a merely linguistic competence, an encyclopaedia reflects the cultural codes associated with the interpreted word, and an encyclopaedia-like representation takes into account “the whole of our world knowledge.”<fnref n="92" /> Acknowledging the limited utility of dictionary representations alone, adjudicators appear to find the encyclopedia representations they seek by contextualizing the initially “raw” meaning of terms they find in dictionaries.

<footnote n="54">Sotirios-Ioannis Lekkas, Panos Merkouris & Daniel Peat, “The Interpretative Practice of the International Court of Justice” (2023) 26:1 Max Planck YB United Nations L 316 at 325 observe that, “[f]or the most part, the Court limits itself to recalling the terms used in a treaty provision followed by a categorical statement about the Court’s understanding of the ordinary meaning of these terms.”</footnote>

<footnote n="55">Graham Cook, *A Digest of WTO Jurisprudence on Public International Law Concepts and Principles* (Cambridge: Cambridge University Press, 2015) at para 15.3.2.</footnote>

<footnote n="56">Brian A Garner, ed, *Black’s Law Dictionary* (St Paul, MN: Thomson Reuters, 2019).</footnote>

<footnote n="57">*Meriam-Webster’s Dictionary of Law*(Springfield, MA: Merriam-Webster, 2011).</footnote>

<footnote n="58">See *Mexico—Measures Affecting Telecommunications Services* (2004), WTO Doc WT/DS204/R at paras 7.81—82 (Panel Report), online: <wto.org> [perma.cc/WB82-NXPZ] [*Mexico*—*Telecommunications*].</footnote>

<footnote n="59">Van Damme, 2009, *supra* note 52 at 230.</footnote>

<footnote n="60">*Ibid* at 231.</footnote>

<footnote n="61">*United States—Measures Affecting the Cross-Border Supply of Gambling and Betting Services* (2004), WTO Doc WT/DS285/R at paras 6.55—59 (Panel Report), online: <wto.org> [perma.cc/T9EN-997M].</footnote>

<footnote n="62">*United States—Measures Affecting the Cross-Border Supply of Gambling and Betting Services* (2005), WTO Doc WT/DS285/AB/R at para 166 (Appellate Body Report), online: <wto.org> [perma.cc/7Q7E-NN9K] [*US—Gambling 2005*]; for a comment, see Federico Ortino, “Treaty Interpretation and the WTO Appellate Body Report in *US—Gambling*: A Critique” (2006) 9:1 J Intl Econ L 117.</footnote>

<footnote n="63">*Thailand—Anti-Dumping Duties on Angles*,*Shapes and Sections of Iron or Non-Alloy Steel and H-Beams from Poland* (2000), WTO Doc WT/DS122/R at para 7.143 (Panel Report), online: <wto.org> [perma.cc/G6AY-6RVS] [Panel Report, Thailand*—Anti-Dumping*]; *Agreement on Implementation of Article VI of the General Agreement on Tariffs and Trade 1994* (*Anti*-*Dumping Agreement*), 15 April 1994, 1868 UNTS 201.</footnote>

<footnote n="64">*Thailand—Anti-Dumping Duties on Angles*,*Shapes and Sections of Iron or Non-Alloy Steel and H-Beams from Poland* (2001), WTO Doc WT/DS122/AB/R at para 21 (Appellate Body Report), online: <wto.org> [perma.cc/7AHB-F57Z] [Appellate Body Report, Thailand*—Anti-Dumping*].</footnote>

<footnote n="65">Panel Report, *Thailand—Anti-Dumping*, *supra* note 63 at para 107.</footnote>

<footnote n="66">Henrik Horn & Joseph Halevi Horowitz Weiler, “European Communities*—*Trade Description of Sardines: Textualism and its Discontent” (2005) 4:S1 World Trade Rev 248 at 252; Joseph Halevi Horowitz Weiler, “The Rule of Lawyers and the Ethos of Diplomats: Reflections on the Internal and External Legitimacy of WTO Dispute Settlement” (2001) 35:2 J World Intl & Trade 191 at 206 further considers that the “almost obsessive attempts of the Appellate Body to characterize wherever possible the normal wide-ranging, sophisticated, multifaceted and eminently legitimate interpretations of the Agreement as ‘textual’ resulting from the ordinary meaning of words is another manifestation of the internal-external legitimacy paradigm.”</footnote>

<footnote n="67">William Davey, “The WTO Dispute Settlement System: The First Ten Years” (2005) 8:1 J Intl Econ L 17 at 22, n 22.</footnote>

<footnote n="68">Zhang, *supra* note 53 at 428, referring to *India—Quantitative Restrictions on Imports of Agricultural, Textile and Industrial Products* (1999), WTO Doc WT/DS90/AB/R at paras 91*—*92 (Appellate Body Report).</footnote>

<footnote n="69">*US—Gambling 2005*, *supra* note 62 at para 166.</footnote>

<footnote n="70">*ADF Group Inc v United States of America* (2003), Case No ARB (AF)/00/1 at para 161 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="71">See *Marvin Roy Feldman Karpa v United Mexican States* (2002), Case No ARB(AF)/99/1 at para 96 (International Centre for Settlement of Investment Disputes); see also *Alasdair Ross Anderson and others v Republic of Costa Rica* (2010), Case No ARB(AF)/07/3 at para 48 (International Centre for Settlement of Investment Disputes); for more details, see Andreas Kulick & Panos Merkouris, “Article 31 of the *VCLT*: General rule of interpretation” in Andreas Kulick & Michael Waibel, eds, *General International Law in International Investment Law: A Commentary* (Oxford: Oxford University Press, 2024) 120.</footnote>

<footnote n="72">*MTD Equity Sdn Bhd and MTD Chile SA v Republic of Chile* (2004), Case No ARB/01/7 at para 113 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="73">*Tulip Real Estate and Development Netherlands BV v Republic of Turkey* (2015), Case No ARB/11/28 at paras 191*—*93 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="74">Already in 1922, in its advisory opinion on the *Competence of the International Labour Organization in regard to International Regulation of the Conditions of the Labour of Persons Employed in Agriculture*, PCIJ (Ser A/B) No 2 at paras 40*—*45 the PCIJ referred to the French dictionary by Littré and to the *Oxford Dictionary* to determine what it called “the senses in which [the words *industrie* and *industriel*] are used.”</footnote>

<footnote n="75">*Treaty of Amity*,*Economic Relations and Consular Rights*, 15 August 1955, 284 UNTS 93 art X at para 1 (entered into force 16 June 1957).</footnote>

<footnote n="76">*Case Concerning Oil Platforms (Islamic Republic of Iran v United States of America)*, [1996] ICJ Rep 803 at para 45.</footnote>

<footnote n="77">*Ibid* at para 49.</footnote>

<footnote n="78">*Case Concerning Oil Platforms (Islamic Republic of Iran v United States of America)*, Dissenting Opinion of Vice-President Schwebel, [1996] ICJ Rep 874 at 887.</footnote>

<footnote n="79">Bianchi & Zarbiyev, *supra* note 2 at 92, quoting Stanley Fish, “Intention Is all There Is: A Critical Analysis of Aharon Barak’s Purposive Interpretation in Law” (2008) 29:3 Cardozo L Rev 1109 at 1123.</footnote>

<footnote n="80">*United States—Continued Dumping and Subsidy Offset Act of 2000* (2003), WTO Doc WT/DS217, 234/AB/R at para 248 (Appellate Body Report), online: <wto.org> [perma.cc/LZ6E-6JKJ].</footnote>

<footnote n="81">*United States—Final Countervailing Duty Determination with respect to certain Softwood Lumber from Canada* (2004), WTO Doc WT/DS257/AB/R at para 59 (Appellate Body Report), online: <wto.org> [perma.cc/NAR7-EREB].</footnote>

<footnote n="82">*US—Gambling 2005*, *supra* note 62 at para 164.</footnote>

<footnote n="83">*Canada—Measures Affecting the Export of Civilian Aircraft* (1999), WTO Doc WT/DS70/AB/R at para 153 (Appellate Body Report); for an illustration, see *European Communities—Measures Affecting Asbestos and Products Containing Asbestos* (2001), WTO Doc WT/DS135/AB/R at para 92 (Appellate Body Report), online: <wto.org> [perma.cc/8Z7G-5348].</footnote>

<footnote n="84">Van Damme, *supra* note 39 at 623.</footnote>

<footnote n="85">*Methanex*, *supra* note 41 at paras 135—36.</footnote>

<footnote n="86">*General Act for the Pacific Settlement of International Disputes*, 26 September 1928, 93 LNTS 344 [*General Act*].</footnote>

<footnote n="87">*Aegean Sea Continental Shelf (Greece v Turkey)*, [1978] ICJ Rep 3 at para 54 [*Aegean Sea*].</footnote>

<footnote n="88">*Ibid*.</footnote>

<footnote n="89">*Vienna Convention on Consular Relations*, 24 April 1963, 596 UNTS 261.</footnote>

<footnote n="90">*Avena and Other Mexican Nationals (Mexico v United States of America)*, [2004] ICJ Rep 12 at para 84.</footnote>

<footnote n="91">Eco, *supra* note 48 at 143.</footnote>

<footnote n="92">Umberto Eco, “Metaphor, Dictionary, and Encyclopedia” (1984) 15:2 New Literary History 255 at 255.</footnote>
# IV. When is “Ordinary Meaning” Ordinary?: The Time Travelling Abilities of “Ordinary
        Meaning”

Determining the ordinary meaning of terms is further complicated by the varying temporal vantage point of the interpreter(s). By definition, a dispute arises after (sometimes long after) the conclusion of the treaty which the adjudicator is called upon to interpret and apply. While the intention of the parties is expressed at the time of the conclusion of the treaty, the interpretative process, which is aimed at ascertaining this intention, takes place later. This temporal difference is sometimes even unconsciously relevant—for instance, the mere use by an adjudicator of a current dictionary (rather than a dictionary from the time of conclusion of the treaty) is already a choice, geared towards what is commonly referred to as “evolutionary interpretation.”<fnref n="93" /> This fascinating topic has received a lot of attention in academic writing, in particular in a recent book edited by Gabrielle Marceau.<fnref n="94" /> The ambition of this article is neither to summarize the many doctrinal positions in this area, nor to provide a revolutionary new one. Nevertheless, an analysis of the ways in which adjudicators determine the “ordinary meaning” of terms would be incomplete if it ignored the question of time. In other words, when determining the “ordinary meaning” of the terms of a treaty, do adjudicators seek to identify what the terms meant at the time of the conclusion of the treaty or what they mean at the time when the question of their interpretation arises?

Starting from the premise that the objective of treaty interpretation is to ascertain the intention of the parties, and that treaties should be interpreted in good faith, adjudicators have in general considered that the meaning of a term has to be established in the light of the meaning of these terms at the time of conclusion of the treaty (principle of contemporaneity).<fnref n="95" /> For instance, in the*Rights of Nationals of the United States of America in Morocco case*, the ICJ had to interpret the word “dispute” contained in a 1836 treaty between the United States and Morocco in order to determine whether it covered only civil cases, or also criminal ones. The Court took into account the meaning of the word at the time when the treaty was concluded, which meant that it covered both civil and criminal disputes (especially since the clear-cut distinction between civil and criminal matters had not yet been developed).<fnref n="96" />

However, it is often the case that the terms used in treaties are of a generic and non-static nature and refer to concepts that are capable of evolving. In its advisory opinion on the *Legal Consequences for States of the Continued Presence of South Africa in Namibia*, the ICJ noted, for instance, that concepts such as “the strenuous conditions of the modern world”, “the well-being and development” of the peoples concerned, or “sacred trust” are “not static, but […] by definition evolutionary.”<fnref n="97" />

The choice of such generic terms is not accidental. They are especially common in certain areas. In trade law, for instance, they reflect the intention of the parties to a trade agreement to “allow the rights and obligations under that agreement to evolve with the changing circumstances and situations in which they were to be applied.”<fnref n="98" /> As Gabrielle Marceau pointed out, the issue of changes is particularly relevant in the WTO context because the WTO treaties “combine long-standing provisions with other, more recent ones.”<fnref n="99" /> Generic terms are also widespread in international investment agreements in provisions regarding the “promotion”, “protection” and “treatment” of investments or “umbrella clauses.”<fnref n="100" />

Called upon to interpret such generic non-static terms, adjudicators have often adopted an approach of “evolutionary interpretation.”<fnref n="101" /> This approach is broadly described by Isabelle Van Damme as an interpreter’s decision

> on whether it is necessary to interpret a term or phrase in a treaty in a manner that takes account of either legal or factual developments subsequent to a treaty’s conclusion, meaning developments not known to the treaty drafters at the time of the treaty’s conclusion and/or that might not have been known by judges who had previously interpreted the same term or phrase.<fnref n="102" />

The choice of evolutionary interpretation may be explained by the interpreter’s sense that the original meaning of a term is probably unable to fit reasonably with the changing circumstances of an evolving world, and that the treaty equilibria would be upset by adhering to this original meaning.<fnref n="103" />

The ICJ has occasionally found that the existence of generic terms in certain treaties invites the interpretation of these terms in light of subsequent developments. In the Court’s view, this is not at odds with but inherently dictated by the parties’ intention, to the extent that

> there are situations in which the parties’ intent upon conclusion of the treaty was, or may be presumed to have been, to give the terms used—or some of them—a meaning or content capable of evolving, not one fixed once and for all, so as to make allowance for, among other things, developments in international law.<fnref n="104" />

For instance, in the *Aegean Sea Continental Shelf case*, the Court considered that the term “territorial status of Greece” used in a reservation by Greece in its accession to the 1928 *General Act*,<fnref n="105" /> was generic in nature, which led to the presumption that “its meaning was intended to follow the evolution of the law and to correspond with the meaning attached to the expression by the law in force at any given time.”<fnref n="106" /> In the Dispute regarding *Navigational and Related Rights (Costa Rica v Nicaragua)*, the ICJ found that the term “*comercio*” used in a 1858 *Treaty of Limits*<fnref n="107" /> had to be understood to have “the meaning [it] bears on each occasion on which the Treaty is to be applied, and not necessarily [its] original meaning.”<fnref n="108" />

In practice, the ICJ chooses the “present meaning” of a generic term in a treaty for purposes of applying the treaty.<fnref n="109" /> This “present meaning” is rarely inconsistent with the traditional meaning of the interpreted term. More often than not, it is a nuance thereof, includes additional elements that may not have existed before, or takes into consideration new developments or new knowledge. In that sense, one may wonder: is this a different, new, interpretation, or is it merely the application of a generic term to the current, new circumstances?

In this regard, Graham Cook argues that, in the interpretative practice of trade adjudicators, what is observable is the latter (“evolutionary application”) rather than the former (evolutionary interpretation in the sense of rejecting the “ordinary meaning” of a treaty term in favour of its “contemporary meaning”).<fnref n="110" /> The most illustrative example in this sense may be the Appellate Body’s interpretation of the term “exhaustible natural resources” in Article XX(g) of the *GATT 1994* in *US*—*Shrimp*.<fnref n="111" /> According to the Appellate Body, this term, crafted more than 50 years prior, was not “static” and had to be “read by a treaty interpreter in the light of contemporary concerns of the community of nations about the protection and conservation of the environment.”<fnref n="112" /> Given recent developments in international cooperation, the Appellate Body considered it “too late in the day to suppose that Article XX(g) of the *GATT 1994* may be read as referring only to the conservation of exhaustible mineral or other non-living natural resources.”<fnref n="113" /> Following a similar logic, the panel in *India*—*Solar Cells* found that the terms “products in general or local short supply” in Article XX(j) of the *GATT 1994* were not static in their “content or reference” but rather generic. Yet, in the panel’s view, this did not mean that the applicable legal standard for what it meant to be a “product in general or local short supply” had changed over time.<fnref n="114" />

Trade adjudicators have also adopted an evolutionary reading of the terms used in WTO Members’ schedules of concessions or commitments, possibly conscious of the rapidly evolving nature of goods and services. In *China*—*Publications and Audiovisual Products*, the Appellate Body considered that some terms used in China’s *General Agreement on Trade in Services*<fnref n="115" /> Schedule (namely, “sound recording” and “distribution”) were “sufficiently generic that what they apply to may change over time.”<fnref n="116" /> Interestingly, in a similar context of interpreting schedules of concessions, the panel in *EC*—*IT Products*did not consider it necessary to resort to “any form of evolutionary interpretation”, having found that the ordinary meaning (presumably—the original meaning) of the interpreted terms already covered a wide range of characteristics and technologies.<fnref n="117" />

There are scarce examples where investment tribunals have resorted to evolutionary interpretation. In *Mondev International v US*, the tribunal, interpreting the terms “fair and equitable treatment” and “full protection and security” contained in Article 1105(1) of the *NAFTA*, opted for what it called a “reasonable evolutionary interpretation”, rejecting the idea that the content of the minimum standard today was “limited to the content of customary international law as recognised in arbitral decisions in the 1920s.”<fnref n="118" /> This approach is, however, rare in the practice of investment arbitrators. As Makane Moïse Mbengue and Aikaterini Florou report, investment tribunals “are not keen on admitting that they engage in evolutionary interpretation” and prefer to use “more neutral language.”<fnref n="119" />

<footnote n="93">See in this sense Marquet, *supra* note 42 at 197.</footnote>

<footnote n="94">Georges Abi-Saab et al,*supra* note 42.</footnote>

<footnote n="95">Crawford, *supra* note 13 at 367.</footnote>

<footnote n="96">*Rights of Nationals of the United States of America in Morocco (France v United States of America)*, [1952] ICJ Rep 176 at 189.</footnote>

<footnote n="97">*Legal Consequences for States of the Continued Presence of South Africa in Namibia (South West Africa) Notwithstanding Security Council Resolution 276 (1970)*, Advisory Opinion, [1971] ICJ Rep 16 at para 53.</footnote>

<footnote n="98">Peter Van den Bossche, “Is there evolution in evolutionary interpretation of WTO law?” in Georges Abi-Saab et al, *supra* note 42, 221—28.</footnote>

<footnote n="99">Gabrielle Marceau, “Evolutive Interpretation by the WTO Adjudicator: Sophism or Necessity?” (2018) 21 J Intl Econ L 791—92.</footnote>

<footnote n="100">Makane Moïse Mbengue & Aikaterini Florou, “Evolutionary Interpretation in Investment Arbitration: About a Judicial Taboo” in Georges Abi-Saab et al, *supra* note 42, 253 at 253.</footnote>

<footnote n="101">For extensive descriptions, see Sondre Torp Helmersen, “The Evolutionary Treaty Interpretation by the WTO Appellate Body” in Georges Abi-Saab et al, *supra* note 44, 207; Van den Bossche, *supra* note 100.</footnote>

<footnote n="102">Isabelle Van Damme, “Understanding the Choice for Evolutionary Interpretation” in Georges Abi-Saab et al, *supra* note 42, 171 at 171.</footnote>

<footnote n="103">Eirik Bjorge & Robert Kolb, “The Interpretation of Treaties over Time” in Duncan B Hollis, ed, *The Oxford Guide to Treaties*, 2nd ed (Oxford: Oxford University Press, 2020) 489 at 490.</footnote>

<footnote n="104">*Dispute regarding Navigational and Related Rights (Costa Rica v Nicaragua)*, [2009] ICJ Rep 213 at para 64 [*Costa Rica*].</footnote>

<footnote n="105">*General Act*, *supra* note 86.</footnote>

<footnote n="106">*Aegean Sea*, *supra* note 87 at para 77; in the subsequent case of the *Navigational and Related Rights* between Costa Rica and Nicaragua, the ICJ explained that its reasoning in *Costa Rica*, *supra* note 104 at para 66 was “founded on the idea that, where the parties have used generic terms in a treaty, the parties necessarily having been aware that the meaning of the terms was likely to evolve over time, and where the treaty has been entered into for a very long period or is ‘of continuing duration’, the parties must be presumed, as a general rule, to have intended those terms to have an evolving meaning.”</footnote>

<footnote n="107">*Treaty of Limits between Costa Rica and Nicaragua*, 15 April 1858.</footnote>

<footnote n="108">*Costa Rica*,*supra* note 104 at para 70; accordingly, the Court found that the right of free navigation applied to the transport of persons as well as the transport of goods, as the activity of transporting persons could be commercial in nature at the time of the Court’s decision.</footnote>

<footnote n="109">*Ibid*.</footnote>

<footnote n="110">Graham Cook, “The Illusion of ‘Evolutionary Interpretation’ in WTO Dispute Settlement” in Georges Abi-Saab et al, *supra* note 42, 181 at 192—93.</footnote>

<footnote n="111">*General Agreement on Tariffs and Trade 1994*, 15 April 1994, 1867 UNTS 190 art XX(g), Annex 1A to the *Marrakesh Agreement*,*supra*note 19 (entered into force 1 January 1995) [*GATT 1994*]; for detailed comments, see Brigitte Stern, “Interpretation in international trade law” in Fitzmaurice, Elias & Merkouris, *supra* note 22, 111 at 119—20.</footnote>

<footnote n="112">*United States*—*Import Prohibition of Certain Shrimp and Shrimp Products*(1998), WTO Doc WT/DS58/AB/R at paras 129—30 (Appellate Body Report), online: <wto.org> [perma.cc/8VV6-UFL8].</footnote>

<footnote n="113">*Ibid* at para 131; it is worth noting that—with fewer explanations—panels had already adopted a similarly progressive interpretation of Article XX(g) in prior disputes; in *Canada*—*Measures Affecting Exports of Unprocessed Herring and Salmon* (1998), GATT Doc L/628, 35th Supp BISD (1998—89) 98 at para 4.4, online: <wto.org> [perma.cc/V6SN-MTLF] the GATT panel agreed with the parties that salmon and herring stocks were “exhaustible natural resources”; in *United States*—*Standards for Reformulated and Conventional Gasoline* (1996), WTO Doc WT/DS2/R at para 6.37 (Panel Report), online: <wto.org> [perma.cc/XQ6C-KSDN] the panel found that clean air was an exhaustible natural resource, noting that “the fact that a resource was renewable could not be an objection.”</footnote>

<footnote n="114">*India*—*Certain Measures Relating to Solar Cells and Solar Modules*(2016), WTO Doc WT/DS456/ R at paras 7.232—33 (Panel Report), online: <wto.org> [perma.cc/L4H4-JGZ4].</footnote>

<footnote n="115">*General Agreement on Trade in Services*, 15 April 1994, 1869 UNTS 183, Annex 1B to the *Marrakesh Agreement*, *supra* note 17.</footnote>

<footnote n="116">*China*—*Measures Affecting Trading Rights and Distribution Services for Certain Publications and Audiovisual Entertainment Products*(2009), WTO Doc WT/DS363/AB/R at para 396 (Appellate Body Report), online: <wto.org> [perma.cc/KQ4C-PNTB].</footnote>

<footnote n="117">*European Communities and its Member States*—*Tariff Treatment of Certain Information Technology Products* (2010), WTO Doc WT/DS375, 376, 377/R at para 7.600, n 807 (Panel Report), online: <wto.org> [perma.cc/LR6F-ZSWK].</footnote>

<footnote n="118">*Mondev International Ltd v United States of America* (2002), Case No ARB(AF)/99/2 at para 123 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="119">Mbengue & Florou, *supra* note 100 at 254—55.</footnote>
# V. What is “Ordinary” and What is Special?

In addition to “ordinary meaning” in Article 31(1), the rules of interpretation in the *VCLT* refer to another “type” of meaning—“special meaning”, in Article 31(4). The use of these two terms may appear to some as a distinction, and to others—as a superfluous repetition. On the one hand, given the dictionary definition of “ordinary” as “customary, usual”, the word “special” itself carries the opposite connotation, i.e. “unusual”, “out of the ordinary.” On the other hand, if followed correctly, the interpretative process set out in Article 31(1) is supposed to lead the interpreter to the most appropriate meaning of the term as it is used in the treaty. This is why some members of the ILC considered the concept of “special meaning” redundant, noting that “technical or special use of the term normally appears from the context and the technical or special meaning becomes, as it were, the ordinary meaning in the particular context.”<fnref n="120" /> The ILC ultimately chose to keep the wording of Article 31(4), which would envisage a “somewhat exceptional case where, notwithstanding the apparent meaning of a term in its context, it is established that the parties intended it to have a special meaning.”<fnref n="121" /> The academic view is that the function of Article 31(4) is related to the allocation of the burden of proof on the party invoking the special meaning of the term,<fnref n="122" /> and the strictness of the proof required.<fnref n="123" /> An example in that sense can be found in the PCIJ’s judgment on the Legal Status of Eastern Greenland:

> [t]he geographical meaning of the word “Greenland”, i.e. the name which is habitually used in the maps to denominate the whole island, must be regarded as the ordinary meaning of the word. If it is alleged by one of the Parties that some unusual or exceptional meaning is to be attributed to it, it lies on that Party to establish its contention. In the opinion of the Court, Norway has not succeeded in establishing her contention.<fnref n="124" />

The most obvious way in which the parties would attach a special meaning to the terms of a treaty would be by defining them in the “definitions” article of the treaty.<fnref n="125" /> As Richard Gardiner points out, beyond that, there is scarce practice showing clearly what would amount to sufficient evidence to demonstrate that the parties intended to give special meaning to a term, and adjudicators have generally been reluctant to class a meaning as “special” if there is a way for it to be characterized as “ordinary.”<fnref n="126" />

The ICJ has occasionally rejected the existence of “special meaning.” For example, in the case on the *Application of the International Convention on the Elimination of All Forms of Racial Discrimination*, it rejected Russia’s contention that the word “dispute” used in Article 22 of the *International Convention on the Elimination of All Forms of Racial Discrimination* (*CERD*)<fnref n="127" /> had a special meaning that was narrower than that to be found in general international law. The Court relied, in particular, on the consistent usage of the word throughout the *CERD*, which suggested that there was no reason to depart from its generally understood meaning in Article 22.<fnref n="128" />

Focused on interpreting occasionally more technical terms, WTO adjudicators have oscillated between adopting a very similar approach and envisaging more openly the possibility that terms may have a special meaning.

In the first vein, for instance, the panel in *India*—*ICT Products* rejected India’s argument that its WTO Schedule, which forms part of the *GATT 1994* and the *WTO Agreement*, should be given a “special meaning” because the participants to the *Information Technology Agreement* (*ITA*),<fnref n="129" /> an agreement agreed to solely by some WTO Members after the entry into force of the *WTO Agreement*, intended to limit the scope of a commitment. In the panel’s view, the *ITA* could not signal the intentions of the parties to the *WTO Agreement* with respect to any of its treaty terms (including the terms set forth in India’s WTO Schedule).<fnref n="130" />

In the second vein, the panel in *Mexico*—*Telecoms* considered that the words “interconnection” and “cost-oriented” were technical terms that appeared in specialized service sectors, and that, accordingly, it had to examine what “special meaning” they may have in the telecommunications context. After consulting specialized dictionaries and other references it considered relevant, the panel found that, for both terms, the ordinary meaning was either “confirmed” by the examination of any “special meaning” or was consistent with such “special meaning.”<fnref n="131" />

An interesting illustration of the blurred lines between the concepts of “ordinary meaning” and “special meaning” can be found in a comparison between the ways in which the panel in *Mexico*—*Telecoms* and the investment tribunal in *Aguas del Tunari v Bolivia* characterized their approaches. In both cases, the adjudicators engaged with arguments suggesting that the words used in the relevant treaties had been negotiated and existed in highly specialized contexts. For the panel in *Mexico*—*Telecoms*, this justified looking for “special meaning” in the technical context. For the investment tribunal in *Aguas del Tunari v Bolivia*, this was part of the “ordinary meaning” of the terms in their context. Having found no indication that the parties to the BIT had intended to give special meaning to the term “controlled”, the tribunal observed that the negotiators of the treaty “likely possessed a sophisticated knowledge of business and law”, and “[f]or such persons, the ordinary meaning of a word or phrase also includes the legal meanings given to such words or phrases.”<fnref n="132" />

In general, investment treaties, despite their variety and sophistication, tend to use similar terms. On some occasions, parties to disputes have found meaning in the choice made by the negotiators of a specific bilateral investment treaty (BIT) to depart from the terms generally used in other BITs or in customary international law. Tribunals have, however, mostly rejected such arguments. For instance, in *Parkerings v Lithuania*, the complainant argued that the terms “fair and reasonable treatment” used in the treaty held the host state to a stricter standard of conduct than the standard of “fair and equitable treatment” more commonly found in BITs. The tribunal rejected this argument, finding no evidence which could demonstrate that, when signing the treaty in question, the parties had intended to give a different degree of protection to their investors than the protection granted by the “fair and equitable” standard.<fnref n="133" /> Similarly, the tribunal in *Siemens v Argentina* rejected Argentina’s argument that the dispute settlement clause in the *Germany*—*Argentina BIT*<fnref n="134" /> had to be differentiated from the usual interpretation given to certain terms because it departed from the standard BITs of Germany. In the tribunal’s view, “when the intention of the parties has been clearly expressed, it is not in [the tribunal’s] power to second-guess their intentions by attributing special meaning to phrases based on whether they were or were not part of a model draft.”<fnref n="135" />

The practice of investment tribunals thus generally aligns with the ICJ and some trade adjudicators’ approach of requiring a considerably high threshold for a party to demonstrate “special meaning.” A common explanatory factor for this choice in the field of investment arbitration may be related to the specific role of investment adjudicators, who—by definition—are called upon to interpret a treaty to which only one of the parties to the dispute (the host State) is party, whereas the other party to the dispute (the investor) is not.<fnref n="136" /> With respect at least to some multilateral investment treaties, Thomas W Wälde finds also a practical reason for this approach. In his view, a professional interpreter looking for meaning behind often minor textual differences “will be tempted to think of a ‘special meaning’ when, in fact, there was nothing but some rough cobbling together of language from several model treaties with no proper understanding at this time as to what these changes may be taken to mean.”<fnref n="137" />

<footnote n="120">“Draft Articles”, *supra* note 6 at para 17; this view is, however, not universal, for instance, for Mark Eugen Villiger, *Commentary on the 1969 Vienna Convention on the Law of Treaties* (Leiden: Martinus Nijhoff, 2009) at 434: “special meaning goes beyond, and no longer corresponds with, the apparent ordinary meanings of the term.”</footnote>

<footnote n="121">“Draft Articles”, *supra* note 6 at para 17.</footnote>

<footnote n="122">*Ibid* at para 11.</footnote>

<footnote n="123">See Gardiner, *supra* note 8 at 338—39.</footnote>

<footnote n="124">*Legal Status of Eastern Greenland* (1932), PCIJ (Ser A/B) No 53 at para 111.</footnote>

<footnote n="125">Hill, *supra* note 7 at 255.</footnote>

<footnote n="126">Gardiner, *supra* note 8 at 337—38.</footnote>

<footnote n="127">*International Convention on the Elimination of All Forms of Racial Discrimination*, 7 March 1966, 660 UNTS 195.</footnote>

<footnote n="128">*Application of the International Convention on the Elimination of All Forms of Racial Discrimination (Georgia v Russian Federation)*, Preliminary Objections, [2011] ICJ Rep 70 at para 29.</footnote>

<footnote n="129">WTO, *Ministerial Declaration on Trade in Information Technology Products*, WTO Doc WT/MIN(96)/16 (1996), online: <docsonline.wto.org> [perma.cc/47EJ-LSH8] [*ITA*].</footnote>

<footnote n="130">*India*—*Tariff Treatment on Certain Goods in the Information and Communications Technology Sector* (2023), WTO Doc WT/DS582/R at paras 7.71—72 (Panel Report appealed), online: <wto.org> [perma.cc/3SYV-2X6N].</footnote>

<footnote n="131">*Mexico*—*Telecommunications*, *supra* note 58 at paras 7.108—17, 7.169—74.</footnote>

<footnote n="132">*Aguas del Tunari*, *supra* note 6 at para 230.</footnote>

<footnote n="133">*Parkerings*-*Compagniet AS v Republic of Lithuania* (2007), Case No ARB/05/8 at para 277 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="134">*Treaty between the Federal Republic of Germany and the Argentine Republic on the Promotion and Reciprocal Protection of Investments*, 9 April 1991, 1910 UNTS 198.</footnote>

<footnote n="135">*Siemens AG v The Argentine Republic* (2004), Case No ARB/02/8 at para 106 (International Centre for Settlement of Investment Disputes).</footnote>

<footnote n="136">See in that sense *Industria Nacional de Alimentos v Peru* (2007), Case No ARB/03/4 (Decision on annulment, dissenting opinion of Sir Franklin Berman) at para 9 (International Centre for Settlement of Investment Disputes): “[e]very case of the interpretation of a BIT by an ICSID Tribunal shares this unusual feature, namely that the Tribunal has to find the meaning of a bilateral instrument, one of the Parties to which (the Respondent) will be a party before the Tribunal, while the other Treaty Party by definition will not.”</footnote>

<footnote n="137">Wälde, *supra* note 24 at 724—37.</footnote>
# —

The introductory part of this article set forth what appeared to be the humble objective of comparing the practice of trade and investment adjudicators and the ICJ in an attempt to detect common trends and differences in their approach towards identifying the “ordinary meaning to be given to the terms of the treaty.” The first conclusion reached is that this objective is neither humble nor attainable. The very task of determining what precisely is “ordinary meaning” and comparing it to “special meaning” already demonstrates that there are probably as many nuances to this question as there are interpreters and adjudicators who have expressed views on the topic. This confirms the ILC’s statement that “the interpretation of documents is to some extent an art, not an exact science.”<fnref n="138" />

Nevertheless, the comparative analysis above allows for the identification, at a very generalized level, of at least two broad trends. First, adjudicators often have the immediate reflex of consulting dictionaries as the starting point of the determination of “ordinary meaning.” Second, regardless of whether these dictionaries have provided them with a satisfactory meaning or not, adjudicators almost immediately proceed to contextualizing this meaning, either as part of their continued quest for the “ordinary meaning” of the interpreted terms, or as part of the next steps in the interpretative process. This is probably explained by the inherent limitations of any attempt to determine the meaning of words by reference to other words. As the investment tribunal in *Saluka v The Czech Republic* put it, some terms (in that case, the normative standard of “fair and equitable treatment”) can sometimes only be defined by terms of almost equal vagueness, and “[t]his is probably as far as one can get by looking at the ‘ordinary meaning’ of the terms.”<fnref n="139" />

<footnote n="138">“Draft Articles”, *supra* note 7 at para 4.</footnote>

<footnote n="139">*Saluka Investments BV v The Czech Republic* (2006), UNCITAL at para 297 (United Nations Commission on International Trade Law).</footnote>