[CentOS] how to show that a filesystem is ACL-enabled?

[Miguel Medalha]

>   
>    can someone clarify this?  is there a command that shows whether a
> filesystem is currently acl-enabled?  and is the mount man page
> simply incomplete in that respect?  thanks.

tune2fs -l /dev/[hda1,sda1]

The values between [ ] are an example only. Replace, of course, with 
your own storage device.

Look at "Filesystem features" and "Default mount options".