+The second form of this method takes two additional arguments,
+\arg{msgIdLanguage} and \arg{msgIdCharset}.
+
+\arg{msgIdLanguage} specifies the language of "msgid" strings in source code
+(i.e. arguments to \helpref{GetString}{wxlocalegetstring},
+\helpref{wxGetTranslation}{wxgettranslation} and the
+\helpref{\_()}{underscore} macro). It is used if AddCatalog cannot find any
+catalog for current language: if the language is same as source code language,
+then strings from source code are used instead.
+
+\arg{msgIdCharset} lets you specify the charset used for msgids in sources
+in case they use 8-bit characters (e.g. German or French strings). This
+argument has no effect in Unicode build, because literals in sources are
+Unicode strings; you have to use compiler-specific method of setting the right
+charset when compiling with Unicode.
+
+By default (i.e. when you use the first form), msgid strings are assumed
+to be in English and written only using 7-bit ASCII characters.
+
+If you have to deal with non-English strings or 8-bit characters in the source
+code, see the instructions in
+\helpref{Writing non-English applications}{nonenglishoverview}.
+
+