# Review of Content Standard International System of Units (SI Units) September, 2005

1.  This review is intended to assess the potential utility of content
    standards for use and potentially for inclusion in an ISO
    11179-based metadata registry. The review is directed primarily
    toward the utility of the standard itself, rather than to matching
    the standard with specific agency programs. The review covers issues
    such as the subject area, currency, quality, authority, and
    acceptance of the standards. These are factors that need to be taken
    into account no matter what the programmatic application of the
    standard may be.

## 1. Summary

The International Bureau of Weights and Measures (BIPM) was set up by
the [Metre Convention](http://www.bipm.org/en/convention/) and has its
headquarters near Paris, France. It is financed jointly by the Member
States of the Convention and operates under the exclusive supervision of
the [CIPM](http://www.bipm.org/en/committees/cipm/).

Its mandate is to provide the basis for a single, coherent system of
measurements throughout the world, traceable to the International System
of Units ([SI](http://www.bipm.org/en/si/)). This task takes many forms,
from direct dissemination of units (as in the case of mass and time) to
coordination through international comparisons of national measurement
standards (as in length, electricity and ionizing radiation).

The BIPM has an international staff of over 70 and its status vis-à-vis
the French government is similar to that of other intergovernmental
organizations based in Paris. The budget for 2005 is over ten million
euros.

The 11th General Conference on Weights and Measures (1960) adopted the
name *Système International d\'Unités* (International System of Units,
international abbreviation SI), for the recommended practical system of
units of measurement.

The 11th CGPM laid down rules for the prefixes, the derived units, and
other matters. The **base units** are a choice of seven well-defined
units that by convention are regarded as dimensionally independent: the
metre, the kilogram, the second, the ampere, the kelvin, the mole, and
the candela. **Derived units** are those formed by combining base units
according to the algebraic relations linking the corresponding
quantities. The names and symbols of some of the units thus formed can
be replaced by special names and symbols which can themselves be used to
form expressions and symbols of other derived units.

The SI is not static but evolves to match the world\'s increasingly
demanding requirements for measurement.

##  {#section .unnumbered}

## 2. Identification of Standard {#identification-of-standard .unnumbered}

### 2.1. Title

*Système International d\'Unités* (International System of Units,
international abbreviation SI)

### 2.2. Acronym

SI Units (The document is commonly referred to as the *SI Brochure*)

### 2.3. Web page(s), Identifier, or Contact Information:

### 2.3.1 Web page(s)

http://www.bipm.org/en/si/

### 2.3.2 Identifier

*Système International d\'Unités* (International System of Units,
international abbreviation SI)

### 2.3.3 Contact Information

The BIPM is situated at

> *Pavillon de Breteuil\
> 92312 Sèvres cedex\
> France*

in the Parc de Saint-Cloud near Paris.

Principal contact numbers:

  ----------------------------------------- -----------------------------
  *Telephone (switchboard):*                +33 1 45 07 70 70

  *Fax:*                                    +33 1 45 34 20 21
  ----------------------------------------- -----------------------------

### 2.4 Authority

Under the terms of the Metre Convention, the BIPM operates under the
exclusive supervision of the International Committee for Weights and
Measures (*Comité International des Poids et Mesures*, CIPM), which
itself comes under the authority of the General Conference on Weights
and Measures (*Conférence Générale des Poids et Mesures*,
[CGPM](http://www.bipm.org/en/convention/cgpm/)). The CGPM elects the
members of the CIPM and brings together periodically, at present once
every four years, representatives of the governments of Member States.
The CIPM has established a number of Consultative Committees, which
bring together the world\'s experts in their specified fields as
advisers on scientific and technical matters.

**2.4.1 Creator**

This link contains a directory of Consultative Committees, with contact
information for each.

http://www.bipm.org/utils/en/pdf/directory.pdf

**2.4.2. Acceptance as authoritative**

This is the defining document for the International System of Units.

### 2.5 Publisher

The BIPM (See 2.3.3).

2.6 Language(s)

French and English.

###  3. Content description

### 3.1 Subject area of content and area of application

SI units are divided into two classes:

-   [*base*](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/) units;

-   [*derived*](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/)
    units.

From the scientific point of view, the division of SI units into these
two classes is to a certain extent arbitrary, because it is not
essential to the physics of the subject. Nevertheless, the CGPM,
considering the advantages of a single, practical, world-wide system of
units for international relations, for teaching and for scientific work,
decided to base the International System on a choice of seven
well-defined units which by convention are regarded as dimensionally
independent: the
[metre](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/metre.html),
the
[kilogram](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/kilogram.html),
the
[second](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/second.html),
the
[ampere](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/ampere.html),
the
[kelvin](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/kelvin.html),
the
[mole](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/mole.html),
and the
[candela](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/candela.html).
These SI units are called *base units*.

The second class of SI units is that of *derived units*. These are units
that are formed as products of powers of the base units according to the
algebraic relations linking the quantities concerned. The names and
symbols of some units thus formed in terms of base units may be replaced
by special names and symbols which can themselves be used to form
expressions and symbols for other derived units.

The SI units of these two classes form a *coherent* set of units, where
coherent is used in the specialist sense of a system whose units are
mutually related by rules of multiplication and division with no
numerical factor other than 1. Following CIPM Recommendation 1 (1969;
PV, **37**, 30-31 and *Metrologia*, 1970, **6**, 66), the units of this
coherent set of units are designated by the name *SI units*.

It is important to emphasize that each physical quantity has only one SI
unit, even if this unit can be expressed in different forms. The
inverse, however, is not true; in some cases the same SI unit can be
used to express the values of [several different
quantities](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#single-unit).

### 3.2 Kind of content

Formal definitions of all SI base units are approved by the
[CGPM](http://www.bipm.org/en/convention/cgpm/). The first such
definition was approved in 1889 and the most recent in 1983. These
definitions are modified from time to time as techniques of measurement
evolve and allow more accurate realizations of the base units.

Symbols for base units

The base units of the International System are listed in Table 1 which
relates the base quantity to the unit name and symbol (10th CGPM (1954,
[Resolution
6](http://www.bipm.org/jsp/en/ViewCGPMResolution.jsp?YEAR=1954&CGPM=10&RES=6));
11th CGPM (1960, [Resolution
12](http://www.bipm.org/jsp/en/ViewCGPMResolution.jsp?YEAR=1960&CGPM=11&RES=12));
13th CGPM (1967-1968, [Resolution
3](http://www.bipm.org/jsp/en/ViewCGPMResolution.jsp?YEAR=1967-1968&CGPM=13&RES=3));
14th CGPM (1971, [Resolution
3](http://www.bipm.org/jsp/en/ViewCGPMResolution.jsp?YEAR=1971&CGPM=14&RES=3))).

**SI base units**

  --------------- ----------------------------------------- ------------------------------------------------------------------------------------ --------------------------------------------------------------- ----------------------------------------- --
  Base quantity                                             SI base unit                                                                                                                                                                                   

                                                                                                                                                                                                                                                           

                                                            Name                                                                                 Symbol                                                                                                    

                                                                                                                                                                                                                                                           

  length                                                    [metre](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/metre.html)         m                                                                                                         

  mass                                                      [kilogram](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/kilogram.html)   [kg](http://www.bipm.org/en/si/si_brochure/chapter3/3-2.html)                                             

  time                                                      [second](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/second.html)       s                                                                                                         

  electric                                                  [ampere](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/ampere.html)       A                                                                                                         
  current                                                                                                                                                                                                                                                  

  thermodynamic                                             [kelvin](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/kelvin.html)       K                                                                                                         
  temperature                                                                                                                                                                                                                                              

  amount of                                                 [mole](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/mole.html)           mol                                                                                                       
  substance                                                                                                                                                                                                                                                

  luminous                                                  [candela](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/candela.html)     cd                                                                                                        
  intensity                                                                                                                                                                                                                                                

                                                                                                                                                                                                                                                           

                                                                                                                                                                                                                 ![](media/image1.png){width="0.15625in"   
                                                                                                                                                                                                                 height="0.2604166666666667in"}            
  --------------- ----------------------------------------- ------------------------------------------------------------------------------------ --------------------------------------------------------------- ----------------------------------------- --

  -----------------------------------------------------------------------
  ![](media/image1.png){width="0.10416666666666667in"
  height="5.2083333333333336e-2in"}

  -----------------------------------------------------------------------

**SI Derived Units**

Derived units are units which may be expressed in terms of [base
units](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/) by means of
the mathematical symbols of multiplication and division. Certain derived
units have been given special names and symbols, and these special names
and symbols may themselves be used in combination with those for base
and other derived units to express the units of other quantities.

[Units expressed in terms of base
units](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html): for
[area](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#square-metre),
[volume](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#cubic-metre),
[velocity](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#metre-per-second),
[acceleration](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#metre-per-second-squared),
[wavenumber](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#reciprocal-metre),
[density](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#kilogram-per-cubic-metre),
[specific
volume](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#cubic-metre-per-kilogram),
[current
density](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#ampere-per-square-metre),
[magnetic field
strength](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#ampere-per-metre),
[concentration](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#mole-per-cubic-metre),
[luminance](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#candela-per-square-metre),
[refractive
index](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html#one)

![](media/image2.png){width="0.16666666666666666in"
height="9.375e-2in"}[Units with special names and symbols; units which
incorporate units with special names and
symbols](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html): [radian](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#radian),
[steradian](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#steradian),
[hertz](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#hertz),
[newton](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#newton),
[pascal](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#pascal),
[joule](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#joule),
[watt](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#watt),
[coulomb](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#coulomb),
[volt](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#volt),
[farad](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#farad),
[ohm](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#ohm),
[siemens](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#siemens),
[weber](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#weber),
[tesla](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#tesla),
[henry](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#henry),
[degree
Celsius](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#degree-Celsius),
[lumen](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#lumen),
[lux](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#lux),
[becquerel](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#becquerel),
[gray](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#gray),
[sievert](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#sievert),
[katal](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html#katal)

![](media/image2.png){width="0.16666666666666666in"
height="9.375e-2in"}[Units for dimensionless quantities, quantities of
dimension
one](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-3.html)

### 3.3 Audience(s)

Those who wish to use a system of worldwide uniformity of measurements
and their traceability to the International System of Units (SI).

### 3.4 Related Standards/3.5 Standards Dependencies

See the CMAP "Relationships of Standards and Guidance Documents for SI
Units"

**3.6 Content Quality**

High.

### 4. Currency of Content

### 4.1 Date/4.2 Versions, Updates/4.3 Currency

The SI brochure is published in English as well as the official French.
The most recent edition, the 7th, was published in spring 1998 and a
*[Supplement
2000](http://www.bipm.org/utils/common/pdf/si-supplement2000.pdf):
addenda and corrigenda to the 7th edition (1998)* was added in 2000.

**5. Acceptance**

The **International System of Units** (abbreviated **SI** from the
[French](http://en.wikipedia.org/wiki/French_language) phrase, *Système
International d\'Unités*) is the most widely used [system of
units](http://en.wikipedia.org/wiki/System_of_units). It is the most
common system for everyday
[commerce](http://en.wikipedia.org/wiki/Commerce) in the world, and is
almost universally used in the realm of
[science](http://en.wikipedia.org/wiki/Science).

In [1960](http://en.wikipedia.org/wiki/1960), SI was selected as a
specific subset of the existing
[Metre](http://en.wikipedia.org/wiki/Metre)-[Kilogram](http://en.wikipedia.org/wiki/Kilogram)-[Second](http://en.wikipedia.org/wiki/Second)
systems of units (MKS), rather than the older
[Centimetre-Gram-Second](http://en.wikipedia.org/wiki/Centimetre_gram_second_system_of_units)
system (CGS). Various new units were added with the introduction of the
SI and at later times. SI is sometimes referred to as the [**metric
system**](http://en.wikipedia.org/wiki/Metric_system), especially [in
the United
States](http://en.wikipedia.org/wiki/Metric_system_in_the_United_States),
which has not widely adopted it, and in the [United
Kingdom](http://en.wikipedia.org/wiki/United_Kingdom), where conversion
is only partial. SI is a specific canon of measurements derived and
extended from the *Metric system*; however, not all metric units of
measurement are accepted as SI units.

### 

### 6. Content details

### 6.1 Size statistics (estimated)

There are a total of 72 pages in the downloadable English version, 79 in
French.

### 6.2 Format / Schemas(s)

The brochure may be downloaded free of charge in PDF format in
[English](http://www.bipm.org/utils/en/pdf/si-brochure.pdf) and in
[French](http://www.bipm.org/utils/en/pdf/brochure-si.pdf). Printed
copies may be obtained on application from the BIPM.

Most of the text is also browsable.

**Contents of the SI Brochure**

-   [Preface to the 7th
    edition](http://www.bipm.org/en/si/si_brochure/preface.html)

-   Introduction

    -   Historical Note

    -   [Two classes of SI
        units](http://www.bipm.org/en/si/si_brochure/chapter1/1-2.html)

    -   [The SI
        prefixes](http://www.bipm.org/en/si/si_brochure/chapter1/1-3.html)

    -   [System of
        quantities](http://www.bipm.org/en/si/si_brochure/chapter1/1-4.html)

    -   [SI units in the framework of general
        relativity](http://www.bipm.org/en/si/si_brochure/chapter1/1-5.html)

    -   [Legislation on
        units](http://www.bipm.org/en/si/si_brochure/chapter1/1-6.html)

-   [**SI units**](http://www.bipm.org/en/si/si_brochure/chapter2/)

    -   SI Base Units

        -   [Definitions](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/)

            -   [Unit of length
                (metre)](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/metre.html)

            -   [Unit of mass
                (kilogram)](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/kilogram.html)

            -   [Unit of time
                (second)](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/second.html)

            -   [Unit of electric current
                (ampere)](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/ampere.html)

            -   [Unit of thermodynamic temperature
                (kelvin)](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/kelvin.html)

            -   [Unit of amount of substance
                (mole)](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/mole.html)

            -   [Unit of luminous intensity
                (candela)](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/2-1-1/candela.html)

        -   [Symbols for base
            units](http://www.bipm.org/en/si/si_brochure/chapter2/2-1/#symbols)

    -   [SI derived
        units](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/)

        -   [Units expressed in terms of base
            units](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-1.html)

        -   [Units with special names and symbols; units which
            incorporate units with special names and
            symbols](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-2.html)

        -   [Units for dimensionless quantities, quantities of dimension
            one](http://www.bipm.org/en/si/si_brochure/chapter2/2-2/2-2-3.html)

-   [**Decimal multiples and submultiples of SI
    units**](http://www.bipm.org/en/si/si_brochure/chapter3/)

    -   [SI
        prefixes](http://www.bipm.org/en/si/si_brochure/chapter3/prefixes.html)

    -   [The
        kilogram](http://www.bipm.org/en/si/si_brochure/chapter3/3-2.html)

-   [**Units outside the
    SI**](http://www.bipm.org/en/si/si_brochure/chapter4/)

    -   [Units used with the
        SI](http://www.bipm.org/en/si/si_brochure/chapter4/4-1.html)

    -   [Other non-SI
        units](http://www.bipm.org/en/si/si_brochure/chapter4/4-2.html)

-   [**The writing of SI unit names and
    symbols**](http://www.bipm.org/en/si/si_brochure/chapter5/)

    -   [General
        principles](http://www.bipm.org/en/si/si_brochure/chapter5/)

    -   [SI unit
        symbols](http://www.bipm.org/en/si/si_brochure/chapter5/5-2.html)

    -   [Algebra of SI unit
        symbols](http://www.bipm.org/en/si/si_brochure/chapter5/5-3.html)

    -   [Rules for using SI
        prefixes](http://www.bipm.org/en/si/si_brochure/chapter5/5-4.html)

-   [**Appendix 1. Decisions of the CGPM and the
    CIPM**](http://www.bipm.org/en/si/si_brochure/appendix1/)

    -   [Decisions relating to the establishment of the Système
        International d\'Unités,
        SI](http://www.bipm.org/en/si/si_brochure/appendix1/establish_SI/)

        -   [Practical system of units: establishment of the
            SI](http://www.bipm.org/en/si/si_brochure/appendix1/establish_SI/practical_system.html)

        -   [The
            SI](http://www.bipm.org/en/si/si_brochure/appendix1/establish_SI/the_system.html)

    -   [Decisions relating to base units of the Système
        International](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/)

        -   [Length](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/decisions_length.html)

        -   [Mass](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/decisions_mass.html)

        -   [Time](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/decisions_time.html)

        -   [Electric
            current](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/decisions_electric.html)

        -   [Thermodynamic
            temperature](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/decisions_temperature.html)

        -   [Amount of
            substance](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/decisions_substance.html)

        -   [Luminous
            intensity](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_base_units/decisions_luminous.html)

    -   [Decisions relating to SI derived and supplementary
        units](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_derived_units/)

        -   [SI derived
            units](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_derived_units/decisions_derived.html)

        -   [SI supplementary
            units](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_derived_units/decisions_suppl.html)

    -   [Decisions concerning terminology and the acceptance of units
        for use with the
        SI](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_terminology/)

        -   [SI
            prefixes](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_terminology/4-1.html)

        -   [Unit symbols and
            numbers](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_terminology/4-2.html)

        -   [Unit
            names](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_terminology/4-3.html)

        -   [Units accepted for use with the SI; an example: the
            litre](http://www.bipm.org/en/si/si_brochure/appendix1/decisions_terminology/4-4.html)

-   [**Appendix 2. Practical realization of the definitions of some
    important units**](http://www.bipm.org/en/si/si_brochure/appendix2/)

    -   [Length](http://www.bipm.org/en/si/si_brochure/appendix2/realize_length/)

    -   [Mass](http://www.bipm.org/en/si/si_brochure/appendix2/mass.html)

    -   [Time](http://www.bipm.org/en/si/si_brochure/appendix2/realize_time/)

        -   [Unit of
            time](http://www.bipm.org/en/si/si_brochure/appendix2/realize_time/unit_of_time.html)

> [Clock comparisons, time
> scales](http://www.bipm.org/en/si/si_brochure/appendix2/realize_time/clock_comparisons.html)

-   

> [Legal
> time](http://www.bipm.org/en/si/si_brochure/appendix2/realize_time/legal_time.html)

-   [Electrical
    quantities](http://www.bipm.org/en/si/si_brochure/appendix2/electrical.html)

-   [Temperature](http://www.bipm.org/en/si/si_brochure/appendix2/temperature.html)

-   [Amount of
    substance](http://www.bipm.org/en/si/si_brochure/appendix2/substance.html)

-   [Photometric
    quantities](http://www.bipm.org/en/si/si_brochure/appendix2/photometric.html)

### 6.3 Media / Download/6.4 Licensing Issues

The brochure entitled [*The International System of
Units*](http://www.bipm.org/en/si/si_brochure/) is the essential
reference for all those who wish to use the SI correctly. It contains
the official definitions of the base units of the SI, and all the
decisions of the CIPM and CGPM related to the SI, its formalism and use.
The brochure is periodically updated after detailed discussion by the
Consultative Committee for Units
([CCU](http://www.bipm.org/en/committees/cc/ccu/)).

### The brochure may be downloaded free of charge in PDF format in [**English**](http://www.bipm.org/utils/en/pdf/si-brochure.pdf) and in [**French**](http://www.bipm.org/utils/en/pdf/brochure-si.pdf). {#the-brochure-may-be-downloaded-free-of-charge-in-pdf-format-in-english-and-in-french. .unnumbered}

### 6.5 Documentation

The BIPM publishes the official reports of the General Conference
(CGPM):

> ![](media/image3.png){width="0.16666666666666666in"
> height="9.375e-2in"}*Comptes Rendus des Séances de la Conférence
> Générale des Poids et Mesures*

the annual meetings of the CIPM:

> ![](media/image3.png){width="0.1673611111111111in"
> height="9.236111111111112e-2in"}*Procès-Verbaux des Séances du Comité
> International des Poids et Mesures*

and the meetings of the Consultative Committees:

> ![](media/image3.png){width="0.16666666666666666in"
> height="9.375e-2in"}*Rapports des Comités Consultatifs*.

The *Comptes Rendus* and *Procès-Verbaux* are bilingual publications
with the French title being the official one. Following a decision of
the CIPM, since the beginning of 2004 the reports of the Consultative
Committees are only published electronically (on the Internet) and only
in English.