Board Thread:Support Requests - Getting Technical/@comment-4723271-20170504012223/@comment-24757753-20170504080821

Afraid not - the hash symbol has a special meaning in links and so can't be used in page names.

While you can't use them in the page name, you can change the displayed title by using the  magic word like below (just add it anywhere in the page): {&#123;DISPLAYTITLE:Riverdale #1}} Be aware, though, that this means people won't be able to copy the page title to make a link to this page (since it won't match the actual page name).