We have a lot of CTAs for each account and within a CTA there will be multiple tasks assigned to different people. We would like everyone to be able to communicate to each other, and other people, by @mentioning each other in the comment section of a specific task. 

Example: If I assign a task to 1 person and he needs to give me an update, he would write @harris in the comments section. Then if I have another task assigned to someone else, they could do the same thing.

This is better than having them assign me a new task, for which I would be notified the following day. It is also better than having to use chatter to comment on the overall CTA where everyone can view it.