Good day everyone,

I observed this behaviour of "mkdir" under /usr/local/:

$ sudo mkdir -p share/doc/subversion-book-en
$ ls -l -d share/doc/subversion-book-en
drwxr-sr-x 2 root staff 4096 Jan 25 13:10 share/doc/subversion-book-en

The same happens in a root shell. I rather expected to get this:
drwxr-xr-x 2 root root …

Why does group get the 's' bit and becomes 'staff'? Is this normal? If
yes, where is it documented?

Any hints are welcome.

Kind regards,
Stefan