Q's Keystone is Gematria.
Gematria is an alphanumeric code which has been used to communicate information in plain sight. (There's a lot more to the code than just that)
Q isn't the only person using this code to pass information, it is also used by "them".
I've added to this thread because it's about Pizzagate. The pedo code from the Podesta emails is coded with Gematria.
Kappy's video has coded information in it. Symbols, Colours, Shapes, Numbers.