What does the dot mean after -rwxr-xr-x in the ls -l output? [duplicate]

What is the meaning of the dot '.' after last (the rightest one ) 'x' in the second line ? This is the output of

[igor@localhost ~]$ ls -l /usr/local/bin

-rwxr-xr-x  1 root root  113797 Aug 20 05:30 gpib
-rwxr-xr-x. 1 root root   30283 Jul 16 22:48 ibtest

No, this is not the only dot in the output from 'ls -l'. There are many ... but NOT on every line.
(CentOS 6.4 32-bit)

Solution 1:

If you have a look at info ls What\ information, it tells you

Following the file mode bits is a single character that specifies whether an alternate access method such as an access control list applies to the file. When the character following the file mode bits is a space, there is no alternate access method. When it is a printing character, then there is such a method.

GNU 'ls' uses a '.' character to indicate a file with an SELinux security context, but no other alternate access method.

A file with any other combination of alternate access methods is marked with a '+' character.