Hashtags. Hashtags have been contributing in a vast majority of applications people use everyday.

By putting hash tags users can see what's trending, new, etc. Makes it easier for people to search for certain keywords and such.

like twitter?

like twitter?

Kind of like Instagram

Kind of like Instagram

hashtags on any site - what's the difference?

A lot of forums don't allow duplicate discussions in various degrees, so they wouldn't be able to make use of trends.

>i request also this.. for internal use (staff mention, a group...)

Surly the tag system does what you want?