This was a YAST2 supported feature (properly) a long time ago (don't know when
this was removed).

A standard and important feature running an Internet File Server using
something like FTP is to support remote only FTP access (ie no local logon
permissions). I don't know of a single FTP Server which does not support this.

For whatever reason, this feature disappeared from the YAST FTP server applet,
and now only local system users are supported. Of course, this feature has not
disappeared from the FTP Servers themselves.

Because this functionality once existed, I wonder if that earlier YAST applet
code can be researched instead of re-building from scratch? If there has been
fundamental changes in pure-ftpd and vsftpd the code may still need to be
modified.