Translatewiki.net supports MediaWiki and its extensions. There are many extensions actively used and some extensions may not be used at all. We do not really know. What we do know is that some have not been updated for a long time.
The PovWatch extension for instance has not been updated since June 2006 and, it is not clear if this functionality works at all and if so for what releases of MediaWiki. It may be that this extension has never been used. It is not clear that they they have been tested for their functionality.. All this makes extensions like this problematic for Wiki administrators and users alike.
There may be more extensions that are not used but are localised at translatewiki.net. Removing such extensions prevents our localisers from wasting their time.
You can help us by identifying the extensions that are no longer relevant.