I go up a rope or down a rope. Up a tree or a building, down a building/wall or a well. Do some tree trimming, sometimes construction tasks. Mounting stuff disassembling stuff, sending it down, or up another rope. Fun stuff.

Do an internet search for TreeUp.

I think it means workers who, for example, climb on industrial chimneys for maintenance.

Basically anywhere where you're paid for your alpinist skills. Mounting/dismounting things up there. There was an example like cleaning up the walls of an old fortress from grass.