Custom subscription
 

I don't know if this was already suggested in the old suggestion section but I am pretty sure this hasn't yet been suggested here.

I am suggesting to add custom subsription* not subcriptions to a thread or a category but a subscription which informs you only if a criteria is met* a bit like a filter for subscriptions. For example a user could set a subscription in the announcement category and chose to be informed only if the work "Released" is part of the title (to be informed only of releases and not other news). I think this would be a very powerful feature.
Any comments and futher additions to my suggestion are welcome.