FlyerTalk Evangelist
Join Date: Nov 2000
Location: Nashville -Past DL Plat, FO, WN-CP, various hotel programs
Programs: DL-MM, AA, SW w/companion,HiltonDiamond, Hyatt PLat, IHF Plat, Miles and Points Seeker
Posts: 11,072
Though I do not agree with Delta's new ruling, I checked out Southwest's site. If you book any fare other than full fare, you get the following rule:
"Standby travel requires an upgrade to the full unrestricted fare"
I have no idea how this works in practice, but I have seen the signs at the airport and did try once and got that response.