There is no need for any player to have the ability to PM another player saying
"I'm buying a #w, do you happen to have one? 
" or
"#c #c #c #c #c #c #c #c #c :3" and so forth, as well as what Kia345 said about it completely interfering with people's preference of displaying rankings such as
"#1: *kia345" or whatever you choose.
GS1 shouldn't be in the scripted PM window, end of story. That's my opinion and I'm sticking to it.