Q. What does SuDocs mean?

From GPO (the Government Publishing Office) and the Federal Depository Library Program:

The Superintendent of Documents (SuDocs) classification system was developed in the Library of the Government Printing Office between 1895 and 1903. It was first described in 1903 by William Leander Post, then in charge of the Library.  Mr. Post gives credit for the foundation of the system (classification by governmental author) to Miss Adelaide R. Hasse, who used government organization authorship to assign classification numbers to a List of Publications of the U.S. Department of Agriculture from 1841 to 1895. Miss Hasse prepared the list while assistant librarian in the Los Angeles Public Library.

This system has expanded as the Federal Government has grown. Because the classification system is based on the current organizational status of the government author, it changes as the organizational structure of the federal government changes. Thus, publications of some issuing agencies may be located in as many as three different places in the system. Despite this functional weakness, it has stood the test of time as a workable arrangement for uniquely identifying publications issued by the US Government.

https://www.fdlp.gov/catalogingandclassification/cataloging-articles/1791-superintendent-of-documents-sudocs-classification-scheme

Michigan State University has a SuDocs tutorial and quiz here, if you'd like to learn more about the Superintendent of Documents (SuDocs) classification system.

Much of SLU's government documents collection is housed at the Locust Street Library Facility - information here. Please use our Ask A Librarian service if you'd like further assistance with government documents (http://libanswers.slu.edu) or call the Circulation Desk at 314-977-3087.