Priority based on keywords?

I swear this was just discussed but I cannot find the thread in any of my

I don’t want to confuse two different features. I want priority assigned or
added to tickets based on criteria like who the requester is and the contents
of the request. I could just use a procmail filter to dump urgent mail into
an “urgent” queue, but that’s going to require another Queue and will be a
bit of a mess.

Anyone have experience or insight into this?