Description of problem:

The man pages for fstab and fstab-sync contain information that
is in conflict. 

The man page for fstab says this:

  fstab is only read by programs, and not written; it  is  the duty
  of the system administrator to properly create and maintain this
  file.

The man page for fstab-sync says this:
 
  This program serves one major purpose: Update the file  systems
  table file /etc/fstab

That is, fstab-sync does something that the man page for fstab
says is never done: it is a program that writes /etc/fstab.

Either 

1. fstab-sync is terribly terribly wrong in what it does and how it
operates, or

2. The man page for fstab has become out of date.