Techs on RationalWiki are appointed to do—as the title suggests— technical work.
Techs have the ability to (1) alter the edit filter, which affects how RW handles spam and repetitive trolls like Mikemikev, (2) add/remove all user rights, (3) rename users, and (4) alter MediaWiki: space pages, which are mostly user interface items like MediaWiki:Sitenotice (the donation notice) and MediaWiki:Sidebar (the main site sidebar on your left).
However, techs have no community authority and cannot police other users -- unlike moderators.
You can request to be appointed a tech at RationalWiki:Requests for tech rights.
See Special:ListUsers/tech for a list of current techs (there are 16).