Optional messages

I tried to find but did not find anything. I think this should be added to FAQ.

Functionally: Optional messages are not shown by default, and they do not count as untranslated messages when calculating translation percentages.
Practically: Messages which would have translation identical to the source text in majority of languages, but not all, should be marked optional. This includes messages with only proper names for example, which may or may not be transliterated to the target script. Some proper names may also have local names, think of major cities around the world.

Thanks, and how do we make messages optional?

Optional messages are defined in group configuration (currently at http://svn.wikimedia.org/viewvc/mediawiki/trunk/translatewiki/ ). Can be modified by who has access to svn, for example twn staff.

Best place to request additions is here :)

Thank you! ;)