Drawbar dimensions

[Jeepers]

Newbie here, great site, lots of info
I am looking to install a cat 0 3 pont hitch on my tractor and build a few implements for it.
My question is the drawbar hight dimensions.
Is there a standard hight dimension?
I know the width is 20"
Thanks for your help.

 

[Bird]

There's a "standard" for category I, but I don't know about category 0. Try this link.