In 22 months at SKW I've been called 4 times and I openly accept the call (ringtone for Crew Support is Imperial March/Star Wars). JR manning is not mandatory at SKW so I turned 2 down, I just said "sorry can't help you, good luck." 1 I accepted for 150% pay plus positive spacing, the second was at double time with a hotel and positive spacing. When it's not mandatory you can negotiate and when their desperate you'd be amazed at what you can get. They tell us not to negotiate but, hey it's my day off! Tough luck, it's called opportunity cost!