X is a letter that appears in many of the distinctive brand marks of the New Forest. Every commoner who turns out ponies, donkeys or cows must have a registered brand, and mark their animals in a certain way. The Agisters know the brands, so they can see who owns a given pony.
There’s a charge to register a brand. The idea is to discourage people from registering brands they never intend to use. A brand has to be a simple, clear design that is easy to see and describe, otherwise the brands might get confused.
If a person sells a pony to another commoner, the new owner is meant to add their brand behind the original. It’s possible to see ponies with several brands where they’ve been sold on a few times, but it’s unusual.
Foals shouldn’t be branded too young, otherwise the brand will grow along with the foal and end-up looking too big.
Nowadays cattle have to be ‘freeze branded’, but ponies and donkeys can still be hot branded. The branding iron is left in a fire until it becomes red-hot, when just a quick touch against the pony’s side will create a clear mark. The branding doesn’t appear to hurt the ponies or cause any lasting distress.