How did my horse get registered?

So, I have this wonderful yearling Bay Arabian stallion that was accepted to be registered by the Arabian Club, but I have no idea how he was accepted or how he was even up for possibly being registered by them. How did that happen? His name is Ar~ Hotrod Legend.

Here's his url: https://www.equiverse.com/horse.php?id=610587

Thank in advance for the help! I'm still pretty new here and just trying to figure things out.

It looks like you bought the horses from someone else, who probably had applied for registration of your horse.  Since you now own him you got the notification that he'd been registered!

I've had this happen to two or three of my own horses and was super confused XD

Thank you! I figured that might have been what happened, but was still pretty confused.