This is cool, I didn't realize there are so many. A couple interesting ones:
Warning that a bull is in the area: https://en.wikipedia.org/wiki/File:ISO_7010_W034_warning;_bu...
Don't wear gloves (any idea when this would be the case? Usually it's don't wear a specific kind (like latex vs rubber) of glove): https://en.wikipedia.org/wiki/File:ISO_7010_P028.svg