Delivery of weekly discs is within fifteen days of issue date. Each weekly file contains approximately 1-2 gigabytes disseminated on an average of 23 magnetic tapes each week. Approximately 30,000 magnetic tapes exist for the entire backfile. Each subclass has a short, descriptive title often arranged in a specific hierarchical order designated by dots for indentation levels. Substitute pages are issued from time to time.
Annual subscription includes the basic manual and substitute pages.
This file is available on demand and is updated every two months. Offered as a subscription which consists of a two volume basic manual with semiannual replacement pages for an indeterminate period and the Index to the U.S. Patent Classification System . An alphabetical list of approximately 65,000 common, informal headings or terms which refer to specific classes and subclasses in the Manual of Classification used to categorize patents. There are approximately 67,000 terms contained in this index. It is intended as a means for initial entry into the Classification System and should be especially useful for persons not familiar with the system as well as those who may not be familiar with any particular technology under study.