The TFM includes four volumes. Each volume covers a specific subject and provides information for a particular audience. When applicable changes occur in procedures, policies, or legislation, subject matter experts act at the Department of Treasury, Bureau of the Fiscal Service (Fiscal Service) take the appropriate actions to incorporate them into the TFM. The TFM consists of four types of releases: chapters, bulletins, announcements, and supplements. Generally, chapters are used to update procedures or to provide new instructions when guidance, systems, services, or applicable laws change. When the audience needs immediate notice of changes, bulletins are used to provide instructions or requirements. Bulletins have retention dates and may be or may not be codified into a TFM chapter at a later date. Announcements cover one-time events and are not codified into a TFM chapter. Supplements provide the audience with detailed instructions and guidance for financial reporting and accounting procedures.