Latest nominee: the UAL CA who nonrevved on us (Skywest) a couple days ago. I greeted him as he boarded with a friendly 'welcome aboard, Captain', only to be completely ignored. Same thing happened when we deplaned. Not even a glance of acknowledgement, no 'thanks for the ride,' nothing. And I know he was a nonrev guy, not deadheading.

The complete absence of professional courtesy was just mind-boggling.