Here's another great release of the powerful Advanced Topic Prefix Mod adding a new option to require prefix when is possible and prefixes on search results with other changes, to see what has been changed see the changelog:

[b]Version 2.1.2 - Jul   12/2010[/b]
+ Prefix on Search Results.
+ Option to Require Prefix   when Possible.
+ Avoided query creating a calendar event and on   message index when sort box was disabled.
* The way prefixes are   loaded on post screen it's faster, better and shorter.
*   htmlspecialchars to $smcFunc['htmlspecialchars'].
! Hide Prefix after   Quote Button without Quick Reply.
! Blank image wasn't loaded Adding   a Prefix.
! Undefined index: id Creating a Calendar Event.
!   Fixed: Undefined index: boards leaving boards empty

Customers can upgrade easily, if you aren't a customer you can become one: http://www.smfpacks.com/index.php?action=page;sa=products

Regards