Reading #hash Variables in URI
Most of the time when you have a # (hash) symbol in the URI, the functionality is simply to point to an anchor on the page. This is handled by html and the functionality of your browser. In more advanced situations, this variable can be read by JavaScript to do other things like change content or tabs, or maybe even use some fancy script to scroll you to a point on the page. In the case of usability, knowing the hash variable in your PHP code can be extremely useful.