I've heard listerine spritzed on the tail to help with itchies. ?!?

What color is mare? Is it a no-hair scar or a raised scar? I use black shoe polish on Baxter's chestnuts sometimes, that or waterproof mascara on hairless marks. Used judiciously, show touch up spray works well too.

For eventing, you can do the side shave or braid for tails. I had to shave this year b/c Baxter rubbed out a huge spot on the top of his tail (due to those damn gnats, we think, I was so so so sad), although I actually prefer to braid. If the rub is in the middle, you can braid over it; if the rub is on the side, you can do the shave (and finesse the short hair into the shave as necessary).

...and I whispered to the horse; trust no man in whose eye you don't see yourself reflected as an equal.
-Don Vincenzo Giobbe circa 1700