Cloud: In a nutshell:

19 days of reserve in a 5 week bid month. 16 days off.

15 R days in a 28 day month, 13 days off.

RSV = 24 hour notice, very few of those lines usually, I think contractually it is 10% of the R lines.

RA is on call basically 0130 to 1330, 1.5 hour callout. Some bases are 3.0 callout (ANC?)

RB is on call 1330 to 0130, 1.5 hour callout in Memhis.

There is also RA+ and RB+ which shifts the on call window 6 hours, but that isn't used too often as far as I have seen.