I'm at work, and I need to copy some documents. I always write in black ink; I hate blue ink. So, considering the ever-perplexing dilemma of how do I distinguish the originals from the copies if I get the piles mixed up, as I do sometimes, I think "a-ha! I'll just make a little mark on the originals before I copy them and then I'll know which is which!"
Nothing wrong with THAT idea, right?