The United States patent database is the largest cross-referenced body of technical information in the world, with more than six million US patents granted as of April, 1997. As part of the examination process these patents are assigned to one or more of more than 144,000 classification numbers, which groups that invention with all others containing similar technical features.

The United States Patent and Trademark Office (USPTO) publishes electronic information on CD-ROM in the Cassis series, which is now available for selection by Federal depository libraries through the Government Printing Office (GPO). The Cassis series includes the following patents CD-ROMs:

and the following trademark CD-ROMs:

Federal depository libraries may also select the Cassis USAPat series, which contains facsimile images of US patents from 1994 to the present. An "image" is an actual page of the patent, including all drawings, and looks just like the original printed document. USAPat is a document delivery system, not a search system. Retrieval is only by patent number.

Each Cassis disc must be installed before being used for the first time; use PTDL installation defaults.

Be aware of the scope of your database and the limitations of your search. Encourage your patrons to supplement their Cassis searches with those in other online or Web-based databases, such as the first-page database accessible from the USPTO home page http://www.uspto.gov

To do a serious patent search means searching by classification numbers after checking the Manual of Classification and the Classification Definitions on CD-ROM or in paper format. A keyword search can never be exhaustive, because there is no controlled vocabulary.

Be careful when searching by company names: official company names are often different from their popular name, and the USPTO does not standardize them upon entry into its database.

For further training on these products, it is strongly suggested that depository librarians contact their closest Patent and Trademark Depository Library (PTDL). Each PTDL has an official librarian liaison to the PTDL Program Office who has been trained through annual programs at the USPTO, and would be able to help address your needs. You can obtain a current list of PTDLs directly from the USPTO home page http://www.uspto.gov.

For technical questions regarding the use of USPTO’s Cassis series or USAPat, please call (703) 306-2600. This number will not answer search strategy questions nor provide subject matter instruction. It is only for technical support on the use of CD-ROM products.

Library patrons may use the USPTO’s automated message system at (800) PTO-9199 to obtain general information on the most frequently asked questions about patents and trademarks, seven days a week, 24 hours a day. Callers may also request a number of USPTO publications by leaving their name and address on the message system.

Dave Morrison came to the Patent and Trademark Depository Library Program (PTDLP) office as the thirteenth Patent Fellowship Librarian in October 1996. Dave has been documents librarian and patents and trademarks specialist in the Marriott Library at the University of Utah since January 1987.