Keys with type localestring and iconstring may be postfixed by [LOCALE], where LOCALE is the locale type of the entry. LOCALE must be of the form lang_COUNTRY.ENCODING@MODIFIER, where _COUNTRY, .ENCODING, and @MODIFIER may be omitted. If a postfixed key occurs, the same key must be also present without the postfix.

When reading in the desktop entry file, the value of the key is selected by matching the current POSIX locale for the LC_MESSAGES category against the LOCALE postfixes of all occurrences of the key, with the .ENCODING part stripped.

The matching is done as follows. If LC_MESSAGES is of the form lang_COUNTRY.ENCODING@MODIFIER, then it will match a key of the form lang_COUNTRY@MODIFIER. If such a key does not exist, it will attempt to match lang_COUNTRY followed by lang@MODIFIER. Then, a match against lang by itself will be attempted. Finally, if no matching key is found the required key without a locale specified is used. The encoding from the LC_MESSAGES value is ignored when matching.

If LC_MESSAGES does not have a MODIFIER field, then no key with a modifier will be matched. Similarly, if LC_MESSAGES does not have a COUNTRY field, then no key with a country specified will be matched. If LC_MESSAGES just has a lang field, then it will do a straight match to a key with a similar value. The following table lists possible matches of various LC_MESSAGES values in the order in which they are matched. Note that the ENCODING field isn't shown.

For example, if the current value of the LC_MESSAGES category is sr_YU@Latn and the desktop file includes:

 Name=Foo
 Name[sr_YU]=...
 Name[sr@Latn]=...
 Name[sr]=...

then the value of the Name keyed by sr_YU is used.

Although icon names of type iconstring are localizable, they are not human-readable strings, so should typically not be handled by translation tools. Most applications are not expected to localize their icons; exceptions might include icons containing text or culture-specific symbology.