I added a tagging system to the forum. If you want to address someone, just put and [member=15679][/member] in front of their username. If you want to be notified about mentions to you by e-mail, go to My Forum Account -> My Profile -> Mentions and check E-mail mention notifications.
Test:
[member=1050]RK[/member]
[member=1283]SEHF[/member]
[member=676]blankie[/member]