Board Thread:General Discussion/@comment-25090105-20150905023527/@comment-4731838-20150905090112

The mediawiki site states that, For most parser functions all names and values are expanded, regardless of what is relevant for the result. The branching functions (#if, #ifeq, #iferror, #ifexist, #ifexpr, #switch) are exceptions: for #switch, expanded are the names up to and including the match (or all if there is no match), and the value in the case of a match or if there is no match, the default, if any. So, only the matching value is expanded and all names upto the match are expanded