Filter by tag from URL

I would like a URL that I can add to our website which will load a particular category and tag. I notice that when I select a tag under a particular category the URL does not change. However, taking a wild guess I tried appending the tag ID (found by inspecting the code) as a querystring like so:

http://support.exclaimer.com/list/36967-knowledge-base/?category=14456&tag=15698

This works! However, as I did some fairly hacky things to get there I thought I'd confirm if this is safe to use or if there was a better way to do this.