With conversations, just as in life, you don't delete it. You leave it. Look for this option near the top of any conversation. If you want to leave multiple you can click on them in your inbox, and a popup box will offer this chance.
Do you mean delete posts?
Some forums you can't delete posts. Which I think is BS. I get the hippie metaphysical part of it, that it is already out in the astral plane. But some times you replied to wrong thread or said something wrong. Duplicate.
Admins have access, so if they want to scold you for being bad, they still can, even if post is deleted.
If you allow editing, than it is kinda stupid, to not be able to delete.
I think the new format, I like the alerts. Having trouble finding subscribed/watched threads, but I am sure that is just me. I like when it tells me someone has posted in those threads.
There is a software error, I have seen it in other forums using. You will be told you have reply or have been qouted. So you click on it or go to the thread. Nothing new will be there. You may have to hit refresh or back in and out many times. Doesn't always do it. I have had it here once already.
Downfall, is you go to that thread, see nothing new and move on.
Not sure why, have seen it elsewhere I am running chrome. But I dont think it is on my end. Hitting refresh or going between pages in thread, should show new posts regardless of browser.