I don't believe that you can delete but you can always go in and edit it. I have seen where people have used the edit feature and replaced the writing with stars.
I dont know how they handle it here, but on the boards I run, you can click the report post button (little triangle with a red ! in it) and put please delete in it, and the reason it needs deleted. Like I said, that's how we do it, but I dont know about here..