But why would it show up in a request? Some browsers (Safari?) include it in referers, but hash marks have no business on the Internet. Unless they're in java-thingie. Um. The one whose name I always forget that throws /#/ into the middle of each URL just to be difficult.
Or are you talking about pages of yours that you're revisiting? If you went to #.et cetera on the previous visit, your browser may helpfully fill it in again. That would be the mundane explanation.
But #. ? With a . ? Really? Don't like the looks of that in any case. Isn't a leading dot prohibited in anchors of any kind?