ESTABLISHMENT AND POSTING OF RECURRING EXTRA ASSIGNMENTS. All recurring passenger service work (including deadhead allowances and/or travel time in connection therewith) which is not included in regular work runs will be included in extra assignments and posted in Run Books or on Bulletin Boards in Operators' rooms. Regular sign-on and sign-off points and times, and an outline of the service to be performed, will be set forth in the assignment sheet as posted.