I've never noticed it before and am seeing it on some files, and wondering what it signals.
I havent been able to find reference to it in man or google, but then it is kinda hard to google for.
Example:
Code:
-rw------- 1 root root 1148 Dec 9 10:47 syslog-20151209.gz
-rw-------. 1 root root 0 May 9 2012 tallylog
-rw------- 1 root root 0 Dec 9 10:47 unused.log