15.1 @documentlanguage ll[_cc]: Set the Document Language

The @documentlanguage command declares the current document locale. Write it on a line by itself, near the beginning of the file.

@documentlanguage ll[_cc]

Include a two-letter ISO 639-2 language code (ll) following the command name, optionally followed by an underscore and two-letter ISO 3166 two-letter country code (cc). If you have a multilingual document, the intent is to be able to use this command multiple times, to declare each language change. If the command is not used at all, the default is en_US for US English.

As with GNU Gettext (see Gettext), if the country code is omitted, the main dialect is assumed where possible. For example, de is equivalent to de_DE (German as spoken in Germany).

For Info and other online output, this command changes the translation of various document strings such as “see” in cross-references (see Cross References), “Function” in defuns (see Definition Commands), and so on. Some strings, such as “Node:”, “Next:”, “Menu:”, etc., are keywords in Info output, so are not translated there; they are translated in other output formats.

For TeX, this command causes a file txi-locale.tex to be read (if it exists). If @documentlanguage argument contains the optional ‘_cc’ suffix, this is tried first. For example, with @documentlanguage de_DE, TeX first looks for txi-de_DE.tex, then txi-de.tex.

Such a txi-* file is intended to redefine the various English words used in TeX output, such as ‘Chapter’, ‘See’, and so on. We are aware that individual words like these cannot always be translated in isolation, and that a very different strategy would be required for ideographic (among other) scripts. Help in improving Texinfo’s language support is welcome.

@documentlanguage also changes TeX’s current hyphenation patterns, if the TeX program being run has the necessary support included. This will generally not be the case for tex itself, but will usually be the case for up-to-date distributions of the extended TeX programs etex (DVI output) and pdftex (PDF output). texi2dvi will use the extended TeXs if they are available (see Format with texi2dvi).

In September 2006, the W3C Internationalization Activity released a new recommendation for specifying languages: http://www.rfc-editor.org/rfc/bcp/bcp47.txt. When Gettext supports this new scheme, Texinfo will too.

Since the lists of language codes and country codes are updated relatively frequently, we don’t attempt to list them here. The valid language codes are on the official home page for ISO 639, http://www.loc.gov/standards/iso639-2/. The country codes and the official web site for ISO 3166 can be found via http://en.wikipedia.org/wiki/ISO_3166.