RULE 20. EXTRA BOARD - PASSENGER BRAKEMEN.

    (a) Senior qualified passenger brakemen making application will be assigned to the passenger extra board and will remain on such board for period of 90 days, seniority permitting, unless they elect to exercise seniority in assigned service; pool freight service when pool crews are added, or by displacing the junior brakeman in pool freight service, but will be required to remain on the extra board until they can be relieved by extra passenger brakeman. Senior brakemen on brakemen's extra passenger board will be required to accept bulletined assignments in passenger service, providing no brakemen senior to them make application therefor.  

    (b) When passenger brakemen assigned to the extra board are not available, the senior qualified passenger brakemen of the passenger district not regularly assigned as brakemen and who are available at the terminal, will be used in passenger service until brakemen assigned to the extra passenger board are available.  

    (c) Extra passenger brakemen will be permitted to make minimum of 3000 miles per month. Extra passenger brakemen will register their accumulated mileage upon their arrival at home terminal in a book provided for that purpose. Failing to so register their mileage, they will not be entitled to their turn out. This rule shall not be construed as a guarantee.