See CommunityLocalNamesDiscussion for a discussion. See Oddmuse:Local Names Extension for the documentation.
Basically every named link [URL name] (on this page only!) will automatically link name to URL (on the entire wiki) unless a page exists on this wiki with the correct name. Just link to the name as if it existed locally, eg. [[name]].
Our extended local name definitions:
Specific to this wiki:
more local names:
facebook community-wiki, explained
facebook friends community-wiki
facebook friends community-wiki, explained
facebook - group community-wiki
facebook - page community-wiki
facebook page community-wiki, explained
google plus community-wiki, explained
google plus page community-wiki
google - plus page community-wiki
google plus page community-wiki, explained
google-plus-page-community-wiki-feed