Originally Posted by AlaskaBound

Registered Travel Companion = No documentation and travels on a lower priority than you or your spouse/domestic partner but higher than buddy pass. They pay something similar to yield fare. This is how it was at Mesaba. Not sure on exact details with SkyWest.

Domestic Partner = Requires proof of partnership for past 6 months at a minimum, e.g.. checking account, morgatge, apartment lease contract and a lot of other things. They travel on the same priority as you do...usually S3C for Delta Connection carriers with your date of hire. You pay imputed income but it's usually quite a bit cheaper than yield fare like a buddy pass or Registered Travel companion. Again, this was the deal between Mesaba and Delta back in the day.