Quoted from CrazyLevi:

HUO means "never been on location."
A show isn't a location. Show games do not take damage, do not get beat up like route games. Having a game at a show or tournament for a couple days is child's play. It's nothing in the grand scheme of things. As long as you take care of it when you are moving it, the game will be zero percent worse off for the wear.
It's really moot anyway. Call your game HUO. People who overshare on sale ads are inviting unneeded scrutiny and nit picking. If you say "Game is HUO except I took it to Allentown once" you deserve what you get (a lot of bullshit from the usual suspects).