The US for one. With my current company I’ve been on the 73,75/76 and 77. All have their own “Flight Manual” issued by the company. I have the Boeing FCOM’s and FCTM for each type and the company stuff includes pretty much the same as the Boeing pubs. Just with additional company specific stuff.
As an aside, a friend of mine in the U.K. was transitioning from the 73 to the A320 and asked to see what was in our company manual for the bus. His comment was that he much preferred the company tailored manual over the Airbus provided manual.