Manual:GlobalFunctions.php

GlobalFunctions.php is a file that contains global functions, including such important functions as wfMsgExt, which is used for internationalisation.

Parameters to wfMsgExt
function wfMsgExt( $key, $options ) can accept the following as options:
 * parse: parses wikitext to html
 * parseinline: parses wikitext to html and removes the surrounding p's added by parser or tidy
 * escape: filters message through htmlspecialchars
 * escapenoentities: same, but allows entity references like  through replaceafter: parameters are substituted after parsing or escaping
 * parsemag: transform the message using magic phrases
 * content: fetch message for content language instead of interface; Also can accept a single associative argument, of the form 'language' => 'xx':
 * language: Language object or language code to fetch message for (overriden by content), its behaviour with parser, parseinline and parsemag is undefined.