Sales catalogue - mares, geldings, colts, but what does H stand for?!

[kit279]

I'm just looking at the Tattersalls sales catalogue and the mares, colts and geldings are indicated by M, C and G respectively. But a few are marked down as 'H' - can anyone put me out of my misery and tell me what H stands for?!!!

 

[s4sugar]

Horse as in stallion.

 

[LaurenM]

Ahh! That makes sense!