RULE 14. REDUCTION IN CREWS OR INCREASES IN MILEAGE.   Reductions in crews or increases in mileage in passenger service from assignments in effect April 1, 1929 shall not be made for the purpose of offsetting these increases in wages, but nothing in this schedule is understood to  prevent adjustment of runs in short turn-around and suburban service that are paid under minimum rules for the purpose of avoiding payment of excess mileage or overtime that would accrue under these rules, without reducing the number of crews.  Such runs may be rearranged, extended, or have mileage changed by addition of new train service; separate pools or assignments may be segregated or divided, provided that crews are not taken off or reduced in number. Added mileage up to mileage equaling the mileage rate divided into the guaranteed daily rate does not change, take from or add to the minimum day's pay, and this added mileage is not to be construed as "increase in mileage" within the meaning of Rules 10 and 14.