Substitutions of the Esperanto alphabet
There are two conventional sets ASCII substitutions for the letters in the Esperanto alphabet that have diacritics, as well as a number of graphic work-arounds. The diacritics of Esperanto were designed with a French manual typewriter in mind, as French was the international language at the time Esperanto was developed. French typewriters have a dead key for the circumflex that can be used in combination with any other key. In handwritten Esperanto, the diacritics pose no problem. However, since the Esperanto letters with diacritics do not appear on standard computer keyboard layouts (French computer  keyboards, unlike manual typewriters, typically assign the circumflex only to letters that bear it in French orthography), various alternative methods have been devised for inputting them or substituting them in type. The original method, suggested by Zamenhof for people who did not have access to a French typewriter, was a set of digraphs in "h", now known as the "Zamenhof-system" or "h-system". With the rise of computer word processing, the so-called "x-system" has become equally popular. With the advent of Unicode and more easily customized computer keyboards, the need for such workarounds has lessened. ASCII transliteration  systems. There are two alternative orthographies in common use, which replace the circumflex letters with either "h" digraphs or "x" digraphs. Another system sometimes noted is a 'QWXY system'; this is a carry-over from an early Esperanto keyboard app named , with which the Q W X and Y keys were assigned to the letters , , , , and the key sequences TX and DY to the letters and . There are also graphic work-arounds such as approximating the circumflexes with carets. H-system. The original method of working around the diacritics was developed by the creator of Esperanto himself, L. L. Zamenhof . He recommended using in place of , and digraphs with for other the circumflex letters. For example, is replaced by , as in for (chance). Where proper orthography has , the letters should be separated with an apostrophe or a hyphen, as in (six-hour) or (airport). Unfortunately, simplistic ASCII-based rules for sorting words fail badly when sorting h-digraphs, because lexicographically words in should follow all words in and precede words in . The word should be placed after , but sorted in the h-system, would appear before . X-system. A more recent system for typing in Esperanto is the so-called  x-system, which uses instead of for the digraphs, including for . For example, is represented by , as in for and for . X-digraphs solve those problems of the h-system: The x-system has become as popular as the h-system, but it has long been perceived as being contrary to the Fundamento de Esperanto. However, in its 2007 decision, the Akademio de Esperanto has issued general permission for the use of surrogate systems for the representation of the diacritical letters of Esperanto, under the condition that this is being done only "when the circumstances do not permit the use  of proper diacritics, and when due to a special need the h-system fixed in the Fundamento is not convenient." This provision covers situations such as using the x-system as a technical solution (to store data in plain ASCII) yet still displaying proper Unicode characters to the end user. A practical problem of digraph substitution that the x-system does not completely resolve is in the complication of bilingual texts. for is especially problematic when used alongside French text, because many French words end in or . "Aux," for example, is a word in both languages ( in Esperanto). Any automatic  conversion of the text will alter the French words as well as the Esperanto. A few English words like "auxiliary" and "Euxine" can also suffer from such search-and-replace routines. One common solution, such as the one used in Wikipedia's MediaWiki software since the intervention of Brion Vibber in January 2002, is to use to escape the to conversion, e.g. "" produces "aux". A few people have also proposed using "" instead of "" for to resolve this problem, but this variant of the system is rarely used. Graphic work-arounds. There are several "ad hoc" workarounds used in email or  on the internet, where the proper letters are often not supported, as seen also in non-ASCII orthographies such as German. These "slipped-hat" conventions make use of the caret (^) or greater than sign (>) to represent the circumflex. For example, "ŝanco" may be written "^sanco, s^anco," or "s>anco." However, they have generally fallen out of favor. Before the internet age, had proposed shifting the caret onto the following vowel, since French circumflex vowels are supported in printing houses. That is, one would write "ehôsângôj cîujâude" for "eĥoŝanĝoj ĉiuĵaŭde." However, this proposal has never been adopted. Substitutions