I don't know if you are replying to me on this lol
if you click on reply with quote or if you put an @ in-front of their name like this @(you need an account to see links), they will get a notification and know that you are speaking to them
Make sure you spell their name correctly though other wise it won't work, for example.
I think @grrawr is sexy <--- This is wrong
I think @(you need an account to see links) is smelly <--- This is right