If you use grep-dctrl in a Debian package, you should depend on the
grep-dctrl package and heed the following compatibility notes:

   * Always call only the "grep-dctrl" executable.
	Although the "grep-status" and "grep-available" symlinks
	are installed by default, this may change in the future.
	Those symlinks are meant for manual - not scripted - use.
        
   * Always specify an explicit file name
        Don't rely on the implicit file name feature.  The system
        administrator may have changed the default file name.

   * Not all features have been with us in every version
	Check if any of the features you use is mentioned in the
	changelog.  Use a versioned dependency on grep-dctrl, if it
	is necessary.

 - ajk