Can someone explain to me how ARM expect to protect its IP if it doesn't publish anything about it? I was under the impression that in order to protect IP, one

Can someone explain to me how ARM expect to protect its IP if it doesn't publish anything about it? I was under the impression that in order to protect IP, one has to either patent it or copyright it, thus some form of publication must be made. If ARM does publish technical documentation (1), ARM has a way to prove infrigement or prior art whenever someone else tries to use their IP without their approval. If ARM doesn't, how can they prove anything? (1) Obviously, if they publish the tech. docs, they might as well help driver implementors, might they not?