Just wondering if anyone knows of a site where I can find out what the branding means on my horse's neck?

It's quite a large brand, has turned his hair white where it is (he's chestnut) and I'm interested to see if I can find out what it means. I met someone who explained them to me on her own horse, but she didn't say where I could find out the info. She said certain symbols meant different things, like whether he was the first foal, or what exact year it was, etc.

He's an old boy (late 20's), so would have been done in the late 80's.

Thanks