This is either one of those features that the board software has or doesn't have (I'm not sure), but user tagging would be a good feature. Basically, if you want to mention another user in a post and and let them know you've done so, you could add the "@" sign before their username (like old Facebook), or maybe the board just recognizes the username (like current Facebook). For instance, instead of writing "JimmyHAD has a really nice Wade & Butcher like that. You should ask him how he got that finish" and then PM'ing Jimmy that you referred to him in a post, you could just write "@JimmyHAD has a really nice Wade & Butcher like that. You should ask him how he got that finish" and the board would change @JimmyHAD a link to Jimmy's profile and alert him that he was tagged in the post. This is just one way in which it might be implemented.