Edit: Previous text was a stupid question.
Essentially what I'm asking is if I install a game of a friend's backup and then buy the game, will Steam realise I already have the files and skip the download?
Wear gaudy colours or avoid display. It's all the same.
Be warned, I will use walls of polysyllables and complex clauses as a defence against lucid argument.
Wand to read a creepy thread?