It means 12 hours of credit. Which may or may not equal 12 hours of pay once the month is over.

6 intl short calls= 72 hours of credit. = 2 hours over guarantee.

BUT, using the rest of my method.....

12 days of long call at 5:15 = 63 hrs + 72 = 135 credit!!

I might have to go back to the drawing board on that one.....it only really works for domestic SC.
I do like the FDX way of calc. res. pay: ALV x 96% = RES guar.

RES guar. / on call days = credit per day (usually 4 and change)

Use one week of vacation (6:00/day x 7 days) 42 HRS.

Expand your 42 hours of vacation to cover as many Res. days as possible. (usually 10)
Put leftover reserve days at the beginning of the month. (usually about 4-5)
Your vacation credit puts your "RAW" score through the roof right off the bat.(not called RAW, its slightly different but the same concept).

TAKE THE ENTIRE MONTH OFF.