(This applies to Air Canada Mainline only)
During the Coverage Award (Unstacking) process PBS may need to deny Prefer Off and/or Avoid Pairings bid lines. There are a number of other bid line options that are not used during the Coverage Award process. These bid line options restrict the way the PBS award by blocking/preventing the awarding of other pairings that may also need to be assigned during the Coverage Award process. Once the Coverage Award process has been completed, bid line options that were not used for coverage will be used to complete your block if necessary.
Please click HERE to view an in depth bulletin that deals with this subject.