Tangent = Opposite/Adjacent is quite simple to memorize. Everything is too simplified these days when it doesn't need to be. The most annoying mnemonic is Please Excuse My Dear Aunt Sally. You know what? Fuck you, Sally.
Oh, it's Parentheses, Exponentials, Multiplication, Division, Addition, Subtraction. It's an elementary Algebra mnemonic. I've hated it the first day I heard it. As for yours.. I've never seen that in my life. What's it mean?