Both Masky and Hoodie know Morse Code, and will tap out messages to each other quite frequently. Several others have confessed to wanting to learn Morse Code themselves, but have admitted that it's a "Masky and Hoodie thing," and wouldn't be fair to them to take away their secret message of communication. Besides, its kind of fun to try to figure out what they're saying to each other.

(Ok, this was born off of that "Masky and Hoodie have a secret language that nobody has managed to decode" headcannon that I've seen three or four times in different headcannon books. I'll admit, I was tempted to post it here, but in the end I went "nope, not original enough," and came up with this instead. Which, I'll admit, is slightly similar to the other one, but shhh it's fine.)