To continue the history lesson. CoS 94 was introduced unilaterally by a previous DFO, initials GC. In it was the basis of our protection in that one had to OPT IN to be rostered for more than 700 productive (simplistically block) hours. If one did not OPT IN then once one had completed 700 productive hours one became a pumpkin and took the rest of the 'year' off.
The 'productive' year was linked to one's birth month - a fact that worked wonders for those with birthdays at peak leave periods. A friend of mine had a birthday in January. He consistently bid for, and got, leave in Jan and as a BTC had run out of hours by end of Nov. He then decamped to YVR (Whistler) for 3 months R&R. In addition, 5-4-3 ( 5 days off between ULR) protection gave adequate rest protection. What was initially viewed as a disaster by crews actually became a crew friendly tool. And if one opted for more work the excess pay was realistic.
By opting for an OPT IN for excess flying hours rather than OPT OUT from excess flying hours the DFO of the day protected his crews from the 'bean counter' pressure that he was under. The system was rumbled and we went on to all the other CoS / rostering practices that have dogged us since.
Have a Happy New Year