Dieter Baron wrote:
>   However, we should handle if the service is already defined in
> /etc/services:
> 
>   - if it is defined with a different port, error out.
>   - if has been added by another package, only remove it when both
>     packages are deleted.
>   - if it is already present -- not added by a package -- don't remove
>     it.

Also,

    - if the sysadmin has requested that /etc/services not be touched,
      fall back to displaying a message advising of the necessity of the
      change.

-- 
Gillette - the best a man can forget