Board Thread:Support Requests - Getting Technical/@comment-15339176-20150612173432/@comment-2093602-20150614100457

Wikipedia also uses the  symbol (example). It is the standard symbol on the web, there are no alternatives. Do note that Wikipedia is running a newer MediaWiki version which alters the URL after a redirect (like the example above).

By the way it is called the "number sign" or simply "hash", hashtag is twitter speak.