Good point, I intuitively assumed the OP added the # on his own.

But - as so often - it would be best if he gave us a link to where he "frequently saw stuff like" that.

Better than us speculating...

BTW: another option could be that the author is post processing the comments to generate POD and/or other docs.

The examples given look a lot like API docs, like the ones shown in IDE pop-ups.

But that's aforementioned speculation and I doubt this is "frequently seen" ...