Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

DB / Metadata Management Program (MMP): Fundamentals of the NLM® Classification

Page 1 of 1


Classifying Pre-20th Century Works

  • At NLM, works published prior to 1914 are classed either in the WZ schedule or in the 19th Century Scheduleli>
  • The rules for classifying pre-20th century works also apply to reprints and facsimiles of these works
    • These rules do not apply to new editions of early printed works which are classed in the main schedules by topic


Last Reviewed: April 16, 2021