From Fedora Project Wiki
This template is used for several of the test cases in Category:I18n Installation, as they are all pretty much identical except for the name of the language or language group to be tested - we want to test install with various languages, and the procedure is the same for each one.
If the test case is to say 'pick a language from (LANGUAGE GROUP), such as (LANGUAGE GROUP MEMBER #1) or (LANGUAGE GROUP MEMBER #2)' it can be invoked thus:
{{Testcase language install|LANGUAGE GROUP|LANGUAGE GROUP MEMBER #1 or LANGUAGE GROUP MEMBER #2}}
If the test case is to say 'pick the specific language (LANGUAGE)', it can be invoked thus:
{{Testcase language install|LANGUAGE}}