The Duchess of Cambridge is known for her extensive coat collection, and while you've probably realised that she favours a certain colour, you might not have noticed that Kate never takes off her outerwear in public — and the reason why is pretty simple. As pointed out by Harper's Bazaar, taking off your coat in public is apparently seen as an unladylike action, which would explain why the duchess often appears to still be buttoned up once she's stepped inside the various places and organisations that she visits.
Of course, this isn't the only fashion rule that royals have to follow. Clutches are an essential that the Duchess of Cambridge carries with her so that she can "hold her bag in front of her in both hands when shaking hands might be awkward," only one certain shade of nail polish is allowed, and even hosiery seems to be an unspoken royal protocol (although Meghan Markle has already decided to ditch nylons). Read on to see some of Kate's best coats in action.