Comment by Kamil Maciorowski on Using find with -exec gzip and grep

"Find is looking for \; or \+, but reads |." – This statement is wrong. find does not see the | at all, the shell uses it to build the pipe first. And find -exec does not look for \; or \+, it demands ; or +. We need to type \; to protect the semicolon from being interpreted by the shell as a command terminator (see the beginning of this answer).