LC Call Numbers - Long Number
What is this?
Library of Congress numbers start with 1-3 letters followed by a number between 1 and 9999. If a call number has a long number there (greater than 9999), something may have gone wrong.
Why is this trouble?
An LC call number with this pattern may have a typo, such as a repeated
number in it, like: PN10400 .A53 (instead of PN1040)
This call number may or may not match what is on the piece. If the call
number in the system does not match the piece, the book may become lost.
If call number in the system does match the piece, it will be shelved far
from similar books which will impede discovery.
An LC call number with this pattern might be a valid call number of another
type that was mis-coded as an LC call number, like CD17012.
This coding may result in the call number showing up in the wrong reports
(and being omitted from others).
Exceptions
I don't know of any valid LC call numbers matching this pattern.
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 "Long Number" analysis.
If you can search or filter your call numbers by regular expression, look
for call numbers that match the expression /^[A-Z]{1-3}[0-9]{5}/.