The "/search" page:

Search for check-in comments, documents, tickets, or wiki that
match a user-supplied pattern.

   s=PATTERN       Specify the full-text pattern to search for
   y=TYPE          What to search.
                     c -> check-ins
                     d -> documentation
                     t -> tickets
                     w -> wiki
                     e -> tech notes
                     f -> forum
                   all -> everything