From http://posted-stuff.blogspot.com/2011/01/bug-reporting-energy-depleted.html

The author of that blog post tried to search for "capi" to see if a particular crash had already been reported. The default search and a search in all fields failed to find it, but a search specifically in the title text found it.

Default search:
http://bugs.python.org/issue?%40columns=id,activity,title,creator,assignee,status,type&%40sort=-activity&%40filter=status&%40action=searchid&ignore=file:content&%40search_text=capi&submit=search&status=-1,1,2,3

All text:
http://bugs.python.org/issue?%40search_text=capi&ignore=file:content&title=&%40columns=title&id=&%40columns=id&stage=&creation=&creator=&activity=&%40columns=activity&%40sort=activity&actor=&nosy=&type=&components=&versions=&dependencies=&assignee=&keywords=&priority=&%40group=priority&status=1&%40columns=status&resolution=&nosy_count=&message_count=&%40pagesize=50&%40startwith=0&%40queryname=&%40old-queryname=&%40action=search

Title only:
http://bugs.python.org/issue?%40search_text=&ignore=file:content&title=capi&%40columns=title&id=&%40columns=id&stage=&creation=&creator=&activity=&%40columns=activity&%40sort=activity&actor=&nosy=&type=&components=&versions=&dependencies=&assignee=&keywords=&priority=&%40group=priority&status=1&%40columns=status&resolution=&nosy_count=&message_count=&%40pagesize=50&%40startwith=0&%40queryname=&%40old-queryname=&%40action=search