5. Work Letters. For different editions published in the same year, assign a work letter B-Y after the date. (The work letter A is reserved locally for photocopies; Z for incomplete dates).
- Work letters transcribed in 050 _4 are lower case.
- However, for MFHD call numbers, follow the local practice, which may vary by cataloging unit. (SML practice is to capitalize the work letter; Divinity does not capitalize)
- If source copy uses a work letter but no other edition is represented in the file being shelflisted, delete the work letter in the MFHD call number. (Exception: the work letter does not have to be deleted if the source copy is 050 00)
- If variant edition cataloging is created from LC source copy and the variant edition is published in the same year, and Yale does not have the edition cataloged by LC, use the 050 00 call number without a work letter.
6. Photocopies. (Local practice) Photocopies always have a date in the call number; the date is always followed by capital A, e.g. 1893A. The call number date of a photocopy is always the original date of publication, not the date of publication of the photocopy edition. A book originally published by Princeton University Press in 1954 and reprinted as a photocopy by University Microfilms in 1984 would have the call number date 1954A.
For added copies, current practice is to create a separate bibliographic record for the photocopy if the bibliographic record for the first copy is for the original and the copy to be added to the collection is a photocopy. All subsequent photocopies should be recorded as MFHDs linked to the bibliographic record for the photocopy. LC call numbers for copies linked to the photocopy record should have A following the date.
Former practice permitted adding of photocopy MFHDs to a record for the original if the added copy was for the same location. In that case, the date in the call number did not get an A.
Photocopies are generally issued "on-demand" primarily by UMI/Proquest or prepared locally by Yale Preservation. Do not confuse photocopy numbers with call numbers for reprint editions, where a different publisher reissues a set of copies using the same typeface as the original, often including a reproduction of the title page. Reprint edition call numbers take the date of publication (without A), not the date of the original. Rule of thumb: for photocopies, the actual publisher is identified in the 533 field and the original publisher is identified in the 260 field; for reprint editions, the actual publisher is identified in the 260 field and the original publisher is identified in a 500 or 534 field.