Fare class by ??
 

I just looked for flights MSN-LAX on 7/5. During the same search, for the same MSN-DEN flight, I get two different fare class availabilities. They seem to match the DEN-LAX flight.

MSN-DEN UA3684 7/5
F5, A4, JN5, Z3, ZN3, P3, PN4, R0, RN0, IN0, I0, Y9, YN9, B9, M9, E9, U9, H9, HN9, Q9, V9, W9, S9, T8, L6, K5, G3, N1, XN0, X0
DEN-LAX UA372 7/5
See above

MSN-DEN UA3684 7/5
F6, A6, JN6, Z6, ZN6, P6, PN6, R2, RN2, IN0, I0, Y9, YN9, B9, M9, E9, U9, H9, HN9, Q9, V9, W9, S9, T9, L9, K9, G8, N8, XN6, X4
DEN-LAX UA1281 7/5
See above

I thought R availability was by flight, not by trip??

Thoughts?

R space is by flight.

What you are seeing is how the system displays fare class availability based on the most restrictive segment.

That is the case, but united.com doesn't display it that way...If you have more than one segment that OFFERS an 'R' bucket, for some STUPID reason (married segments, I'd guess, but no logic behind it), the website displays the lower of the two quantities of 'R'.

For example, if in reality availability was:

MSN-DEN, R2
DEN-LAX, R0

It displays R0 for for both, even though MSN-DEN has the upgrade space available, and you can confirm into it, you just can't see it.

For your case, you're probably looking at the flight where the other segment has availability in one 'marriage' but not the other.

Stupid.