Version 2.0.2 - 2015-12-02 Menu function to delete "Non-Library Codes Identifiers" changed to also not delete new LC Identifier "loc_lccn".
If you use 'CALM' and also use 'Library Codes', you will want to upgrade sooner rather than later. The loc_lccn Identifier is used to hot-link to the Library of Congress 'permalink' for a book, which is a wonderful source of both author and book information.
Example:
http://lccn.loc.gov/2010013227
DaltonST