Delete your own thread in some forums

[beddows]

We have a buy & Sell forum on our forums. We do not allow people to delete their own threads normally, but we would like them to be able to in thisi section once they have sold an item or bought one. It would be nice to have an option in the individual forum settings for "ability to delete threads you have started". Maybe own posts as well that would overide individual user permissions for that forum.