Hi Adam,
Yep, we still have that request in our database (configurable prefixes) and it's still visible. I'll add your latest comments to the entry so it will get some more visibility during our next release planning sessions.
Another idea would be to store each type of requirement in a separate package file and configure that package file to contain a customized prefix. For example, when you do a right mouse click on a package in the project browswer, you can save it as a separate file. When you do that, you'll be presented with a dialog that will allow you to specify a prefix for the elements. So, if you create package file to store only Functional Requirements, you could give it a prefix of FR- and each new requirement added to that package would be prefixed with REQ-FR-. Just a thought...
Thanks for the feedback,
Jeff