[Zope] what's acl_users mean?

Hi everyone, I'm usually quite good with acronyms, but I can't figure out what the "acl" means in "acl_users." Anyone care to enlighten me? -Tim -- Timothy Wilson | "The faster you | Check out: Henry Sibley H.S. | go, the shorter | http://slashdot.org/ W. St. Paul, MN, USA | you are." | http://linux.com/ wilson@chem.umn.edu | -Einstein | http://www.mn-linux.org/