What does "self tying" mean on a stock?

[StarcatcherWilliam]

I've got my first ever dressage comp coming up and am currently looking for a stock to wear. The one I like isn't available as a ready tied one, but the description says it is self tying - what on earth does that mean?! Sorry if this is a real thicko question lol

 

[Luci07]

ready tied! self tying is not clear... have visions of Jeeve like character popping out from the ether to do it for you!

 

[StarcatcherWilliam]

ready tied! self tying is not clear... have visions of Jeeve like character popping out from the ether to do it for you!

Haha would love that! It's an Equetech one and the others are sold as "ready tied" so a bit strange that these are called self tying when they are the same brand. Confused me, anyway!

Also, I've just seen that I have put this in the wrong place - this isn't to do with horse care and feeding. I'll just get me coat lmao!!