RULE 108. REGISTERING AND CHECKING MILEAGE, (a) Except where charted mileage has been adopted, engineers in all classes of service paying freight rates will register their accumulated mileage on arrival at home point in book provided for that purpose. Failing to so register their mileage they will not be entitled to their turn out. This rule shall not operate to penalize the Company.

(b) In regulating the working lists of engineers in classes of service paying freight rates, adjustments may be made at any time upon the basis of the average mileage for the preceding 7 days, using accumulated mileage as registered by engineers in book provided for that purpose, or the charted mileage where appropriate, as a basis of calculations.