THE BNAPS TECHNICAL REFERENCE SERIES - Railway Cancellations (R.P.O.s)

A Glossary of Terms

used in the Ludlow RPO catalogue (many definitions are reproduced or condensed from Ludlow (1982) - much more detail is found in this publication). A more complete glossary is in preparation. All material is subject to continued improvement by the BNAPS R.P.O. Study Group. Please email the webmaster with suggestions.

  • Cancellation - synonymous with "postmark" recognizing that a postmark becomes a cancellation only when it defaces a stamp. Most railway hammers were used both as cancellation devices and for the application of postmarks and transit markings.

  • R.P.O. - (1) Railway Post Office - specifically, a rail car equipped and staffed for handling of mail.
    (2) A cancellation applied to mail handled by a railway mail car or its equivalent.

  • M.C. - Mail car (see above).

  • Listing - the entire entry for any R. P. O. cancellation of a given type; each major listing is represented by a Listing Number.

  • Sub-Listing - within the permanent lettering of a given listing, there can be one or more variations - such as direction, route, time mark, clerk or steamer name - which do not constitute a major alteration in type; these variations are sub-listed under a major listing number as a self-contained group. This procedure is subject to modification in later editions.

  • Listing Number - The total listings of all railway cancellations have been divided into sections based on geography or purpose; each section has been assigned a prefix of one or more capital letters, as follows:

    Newfoundland
    Maritimes
    Quebec
    Ontario
    Westerns
    Ornaments    		N -
    MA -
    Q -
    O -
    W -
    W + orn't -    		 Railroads and Routes
    registered
    Ticket Stamps
    Steamers
    Depots
    Emergency    		 RR -
    RG -
    TS -
    S -
    DD -
    E

  • Set - includes all removable slug data within the center of a hammer, specifically, the day, month, year, train number, direction and / or time mark.

  • Indicia - includes only that data in the set above the date, specifically, the train number, direction or time mark; somewhat a misnomer, but legitimized by common usage.

    Direction Marks - NORTH, SOUTH, EAST, WEST, N, S, E, W

    Time Marks - AM, PM, or 9:00 AM, NOON, etc. (In Newfoundland, sometimes a letter appears above the date, indicating some indication of time).

    Train Numbers - odd numbers indicate trains that went north or west; even numbers indicate trains that went south or east.

  • Hammer - a cancellation device of steel, rubber or other composition containing permanent, non-replaceable lettering, as shown in each listing under "Cancellation". Although not detailed here, most listings are known with two or more hammers. Identification of each of these multiple hammers varies from simple to difficult, depending on individual characteristics, but all hammers for any given listing will read alike in all major components.

  • Proof - cancellation registered in one of the several Pritchard & Andrews ledgers prior to delivery of the hammer by the maker against government requisition.

  • O.P.K. - "Only Proof Known"; listings with this explanation are known only from the proof strike, and may or may not have been put into actual service.

  • O.D.O.K. - "Only Destruction Order ( strike ) Known"; listings known only from strikes in the official register prior to the destruction of the hammer.

  • ERD - earliest recorded date of use.

  • LRD - latest recorded date of use.

  • Facing Slip - approx. 3" x 5" papers, usually showing run and clerk strike; placed in mail bags after sorting for identification of mail clerk involved.

  • Rarity Factor (RF) - The RF of any given listing represents its relative relationship of scarcity to any others of the published listings, as expressed by their own RFs.

    RR-27, showing circle style RPO, no Hammer designation; May 9, 1896, EAST direction (RR designates a "Railway" category)
    RR-28, Hammer B, August 10, 1888, WEST direction
    RR-29, "LOCAL" Hammer 1, June 27, 1893, EAST direction
    MA-174, circle style with larger spacing between the circle and the RPO name, Mail Car without a Hammer number, 1873, (MA designates a "Maritime" category)
    W-150, (SOURIS & WINNIPEG) M.C. for mail car, squared circle style with no indicia, Hammer No. 1 (W designates a "Western" category)
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