LC Call Numbers - Later Upper Upper

What is this?

One pattern that can show up in LC call numbers in catalogs is two uppercase letters side by side not near the beginning of the call number, like this:

  • Z7164.S66 HM141 W47 1982
  • HD31 .KK655 1985
  • D507 .CS

Why is this trouble?

A call number matching this pattern may be a combination of two call numbers that were in the same bibliographic record field, like: 050 $a Z7164.S66 $b W47 1982 $a HM141. The intent of such fields is to let libraries choose between two locations to class the book; this example is a bibliography related to sociology, so it could go with its topic in sociology (HM141) or with similar bibliographies (Z7164.S66). It's easy enough for a field like this to become a weird mixed call number, so better to record as two separate 050 fields for new records. A call number like this on a book may be confusing for shelvers.

A call number matching this pattern may be an indicator that a letter was accidentally typed twice; so a call number HD31 .KK655 1985 was likely intended to be HD31 .K655 1985 and either version may be on the book's label. If they don't match, it can be harder to find the book. If the double letter is on the label, it may be confusing for shelvers (which comes first, .KK655 or .K345?)

A call number matching this pattern may be an indicator that a call number was mis-read by a person or a computer -- a call number like D507 .C5 could easily be mis-read as D507 .CS, and similar issues happen with 0 and O, 1 and I, 7 and Z, 8 and B, etc. Either version of the call number may be on the book's label. If they don't match, it can be harder to find the book. If the double letter is on the label, it can be confusing for shelvers.

Exceptions

There may be good call numbers matching this pattern, such as in Roman Numerals, enumeration, or abbreviations following the main call number:

  • QP517.B5 I550 1975 XI, XII, XVI
  • JX27 .F7 NO. 72
  • UG630 .T72 1995 SUPPL.

You may also see good call numbers matching this pattern if your library hsa collections with call number prefixes, like:

  • Flat Box SF321 .S74

How to Find

If you are in Alma, there is an analysis to search for this issue in the "Looking for Trouble" folder. Go to the "LC Call Numbers" folder and look for the "Later Upper Upper" analysis.

If you can search or filter your call numbers by regular expression, use the expression /..[A-Z][A-Z]/.