From Homestar Runner Wiki
A Wiki gnome works behind the scenes (of a wiki) to tie up little loose ends, correcting broken links, and just making things run better and smoother.
Wiki gnomes love to work in the shadows (which are called minor edits). Look at Recent Changes and you may even spot one!
Wiki gnomes are good, unlike WikiTrolls.
If you like, you can advertise your Wiki gnome-like qualities on your user page by adding the userbox found on this page.