I wasn't aware of this, and I don't know whether there is an official solution, but... you can make the URL different by adding a hash tag to the end of it. For example:

http://support.mozilla.com/#bmk2

If there actually is a location with that name in the page, the browser will scroll there. Otherwise, it will be ignored. So just make something up and it has a reasonable chance of working.

Hopefully you will get a real answer, too.

Edit: I forgot to mention that you need to add that to the location bar and press Enter to reload the page with that URL in order for Firefox to pick it up.

You can do a Copy & Paste in the Bookmarks Manager (Shift+Ctrl+B) to create a copy of a bookmark.

You can also drag the (fav)icon in the location bar to a folder in the Bookmarks menu drop down list or to a folder in the side bar (Ctrl+B) or to the Bookmarks Toolbar.

In the side bar you need to click to the left of the icon to prevent Firefox from opening the bookmark.

Old Add Bookmark Behavior: https://addons.mozilla.org/firefox/addon/8479

Thanks this worked

Thanks this work also. Much appreciated