If you press QQF in the voice command menu, your character will whistle. This is good to quickly notify allies of enemies outside their vision, and to scare the crap out of an enemy before/while you backstab them. The most useful function is the one that was intended: you can call a horse that has no rider, and it will come over to you. I'm curious about the mechanics of whistling for a horse.
Does whistling call over the closest horse to you by default? Does more riding skill provide any benefit to whistling? Can you override lower riding skill players, or is it just a whistle spamming contest? What about donkeys, which require 0 riding skill? Should anyone be able to call a donkey?
Are there any other non-obvious uses for whistling? How well does a donkey handle with 1 riding skill? If you have any experience to share, I'd be grateful.