Pages that contain or refer to ChrisSiebenmann:
The search looks for things that are (themselves) words. The code implementation will allow spaces and other stuff if you try hard enough. You can search for multiple things at once.
Searching works on the raw wiki-text, before all expansions. Searching does look at page titles, so that looking for 'People' turns up:
which includes all of the People/ pages.
Searches exclude redirection pages, since they are looking at the page contents anyways.
Searches also exclude the current page, because otherwise it gets really irritating.