DHHS publication NIH 00-1535. Revised 5th edition. Incorporates all additions and changes to the classification schedules since the fifth edition was published in 1995. These changes have previously appeared in the "NLM Technical Bulletin." This revision also includes several hundred new entry terms published from 1994 through 1999 in the "NLM Medical Subject Headings Annotated Alphabetic List (MeSH)." Contains copyright material.