linux - How to enable ACL?

I've installed ACL on my Ubuntu:

aptitude install acl

What is the next step ? /etc/fstab ?

  # /etc/fstab: static file system information.
    #
    # Use 'blkid -o value -s UUID' to print the universally unique identifier
    # for a device; this may be used with UUID= as a more robust way to name
    # devices that works even if disks are added and removed. See fstab(5).
    #
    #                
    proc            /proc           proc    nodev,noexec,nosuid 0       0
    # / was on /dev/sda1 during installation
    UUID=54dd976c-b95d-4f44-b4f7-516107dbed85 /               ext4    errors=remount-ro 0       1
    # swap was on /dev/sda2 during installation
    UUID=b03c5549-9b4a-444f-a1ff-6c1e3c767836 none            swap    sw              0       0
    /dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0

Thank you