I just got off the phone with Southwest Customer Relations asking a
question about cabin air pressure. Two separate people informed that
cabin air pressure in flight is 14.7 psi (sea level equiv.) and that it
is 10.0 psi (about 10,000 ft equiv.) on the ground.

Obviously, this has to be backwards, right? Even so, don't regulations
require cabin air pressure to be between 5,000 and 8,000 equiv.
altitude? Wouldn't that mean one of the numbers they gave me would
have to be between 12.23 psi (5,000) and around 11.0 psi (8,000)?

The reason I ask is rather important. My friend has a heart condition
and needs pressure of 4,000 ft or less. Southwest does not allow
supplemental oxygen, and he'd rather not use it anyway. The numbers
they give out seem suspect, and I can't take chances here.
Thanks,
Josh