Freemasonry would be a great candidate for a sticker, as would be any organization that keeps records with dates. The records of Freemasons (and churches and other fraternities) include dates that identify where a specific person was. This would be a great resource for Wikitree and genealogists in general. You can see how I have been using fraternal records as a reference at our category page. Just click on one of the profiles here: https://www.wikitree.com/index.php?title=Category:Kinmundy_Lodge_No._398
A sticker that gives the lodge name and number, its location, and fields for initiation, passing, raising, affiliation, and Past Master would be great. If any of the initiation, passing, and raising fields are missing, alternative text saying "unknown" should appear. If the affiliation or Past Master date fields are missing, the line should be removed from the sticker. The lodge name, number, and location should be required for the sticker to be accepted. You can't say a person was a Freemason without knowing the exact lodge they belonged to. The sticker should automatically be linked to a category specific to that lodge.