Yup, I do mark them, that (and clipping) are the only way to know for sure that they haven't been superceded. Stay tuned for "Beekeeping for Everyone #4" that should come out tomorrow, for my thoughts on supercedure.
Here is a post (and video) on queen marking -> https://steemit.com/howto/@bushkill/how-to-mark-a-honeybee-queen
Thank you so much. I read your post on the bee beard! Very informative :)