XF 2.2 Locked thread to only original poster?

It appears my googlefu is failing me.
Goal - we would like to lock down our buy sell trade node to where only the original poster can make comments in the thread
Problem - We have users that do not understand that we want those conversations, meeting place, negotiation to occur in PM.

Is there a way in Xenforo to do this or an addon that exists?
Hello, from @AndyB
Thank you! I'm embarrassed it was reference so quickly. I tried every combination of user lock thread but kept coming back with the original poster banner. Appreciate the help!


Well-known member
I solved this by not letting anybody reply in the classified-forum and letting poster edit or delete the thread. No need for an add on for me, just permissions.