[Subversion] r123 will produce a link to changeset 123 in Subversion browser
topic:123 will produce a link to topic 123 with its title
post:5 will produce a link to post 123 with the related topic title and the poster username
[Bugtracker] bug 123 will produce a link to bug 123 with its summary, current resolution ("real time" refresh)
[Bugtracker] feature 123 will produce a link to feature 123 with its summary, current resolution ("real time" refresh)
extension:123