This should be an implemented mechanic when entering all towns and villages.
Words contained in posts, at which point I stop reading and will not respond...
Toon / Mana / WoW or any acronym following "In ___" /
Pets (when referring to summoned Daedra) / Any verbiage to express slang (ie, ending in uz,az,..) / Soul Stone
... to be continued.
I notice it a lot in places that are "under siege" when you first arrive. You are not allowed to mount in the area. However, after the siege is resolved, you can mount in the area but for some reason they still force a dismount as you approach certain spots.
This happens a lot around Haven, to an annoying degree. I am to the point where I know exactly where I will be dismounted on all of the approaches to Haven.