Why do have some directories like /var/lib/{docker,sudo} 0711 rights?

Question

I've noticed that the directories /var/lib/{docker,sudo} have 0711 rights (rwx--x--x) by default. Is this some kind of mistake, or why grant someone the right to enter a directory x, without being able to read r it's contents?

Answer 1

This can be useful if subdirectories of /var/lib/{docker,sudo} (not necessarily first-level subdirectories) need to be accessible to other users. To visit any directory, you need to have access permission on all its parents. (See Do the parent directory's permissions matter when accessing a subdirectory?)