The first step of the method places the bottom layer in any order and orientation.
https://www.stefan-pochmann.info//spocc/speedsolving/RoFL/
The thread on speedsolving.com is where the name TCLL came from.
https://www.speedsolving.com/threads/tcll-2x2-method.44438/
https://cyotheking.squarespace.com/tcll