drwxrwxr-x+   2 myuser  another_user   512 Nov 20  2013 foobar

[myuser@hosting_server]$ getfacl foobar
# file: foobar/
# owner: myuser
# group: another_user
user::rwx
group::rwx
mask::rwx
other::r-x

setfacl -b foobar

setfacl -bn foobar

-n      Do not recalculate the permissions associated with the ACL mask
         entry.  This option is not applicable to NFSv4 ACLs.

ls -l | grep foobar
drwxr-xr-x+ 2 maulinglawns maulinglawns 4096 jan 24 14:25 foobar

setfacl -b foobar/
ls -l | grep foobar
drwxr-xr-x 2 maulinglawns maulinglawns 4096 jan 24 14:25 foobar

Distributor ID: Debian
Description:    Debian GNU/Linux 8.7 (jessie)
Release:    8.7
Codename:   jessie