[Toenex]

I think the distinction he was trying to make is that UNIX skills are those that are transferable between UNIX modelled OS's e.g. shell programming, administration, application development. Whereas a Linux pro would be someone whose skills are specifically on that platform. The most obvious reason being kernel programming expertise which is almost the epitome/definition of Linux.

[derekp7]

Could also be someone from a Unix background that also knows specifics of how to optimally manage typical Linux business deployments (usually RHEL, SLES, etc). I can't tell you how many long-time Unix admins I've worked with that didn't know anything about how to create a start/stop init script that was chkconfig compliant (chkconfig originated from Irix I belive), and end up making symlinks in /etc/rcX.d manually. Or be able to debug boot problems (requires knowledge of at least some kernel boot parameters, the initrd, order of the various startup scripts, etc).