  The paper describes in detail the recovery effort of one of the official
MediaWiki grammars. Over two hundred grammar transformation steps are reported
and annotated, leading to delivery of a level 2 grammar, semi-automatically
extracted from a community created semi-formal text using at least five
different syntactic notations, several non-enforced naming conventions,
multiple misspellings, obsolete parsing technology idiosyncrasies and other
problems commonly encountered in grammars that were not engineered properly.
Having a quality grammar will allow to test and validate it further, without
alienating the community with a separately developed grammar.
