(a) The operation of 39 U.S.C. 601(a) (1) through (6) and § 310.2(b) (1) through (6) of this chapter is suspended on all post routes for data processing materials defined in paragraph (c) of this section on the terms detailed in paragraph (b) of this section, subject to the operating requirements in § 320.3.

(b) The suspension referred to in paragraph (a) of this section is for data processing materials conveyed (1) to a data processing center, if carriage is completed within 12 hours or by noon of the addressee's next business day and if data processing work is commenced on such materials within 36 hours of their receipt at the center; or (2) back from the data processing center to the address of the office originating the incoming materials, if carriage is completed within 12 hours or by noon of the addressee's next business day, and if data processing work was commenced on the incoming materials within 36 hours of their receipt at the center. For purposes of the time limitations for completion of delivery referred to in the preceding sentence, delivery of shipments between a domestic point and a foreign point shall be deemed to begin at the time materials of foreign origin are received at the international gateway city or end at the time materials of domestic origin leave the international gateway city. This suspension does not apply to carriages from or to originating offices that are neither part of the firm owning the data processing center nor data processing customers of the firm owning the data processing center.

(c) For purposes of this suspension, (1) “addressee's next business day” means the first calendar day, stated in his local time, on which he conducts business, following the calendar day of dispatch, stated in the sender's local time; (2) “data processing” means electro-mechanical or electronic processing and includes the recording of data by electro-mechanical or electronic means for further processing; and (3) “data processing materials” means materials of all types that are sent exclusively for data processing and are ready for immediate data processing, but only if they are produced recurringly in the course of the normal business operations of the office originating them or receiving them back from the processing center. The performance of clerical work which is merely preparatory and incidental to the commencement of data processing is not, for purposes of this suspension, inconsistent with the requirement that the materials be sent exclusively for data processing and be ready for immediate data processing.