Numerous concise recommendations appear in the notebook volume bearing the number 401.0-B. Each recommendation is dated, and the most recent revision is shown in the table of contents. These Recommendations are developed for conventional near-Earth and deep-space missions having moderate communications requirements. The current issue updates recommendations 2.5.6B and 3.1.6B.

This document issue was superseded by CCSDS 401.0-B-32, Radio Frequency and Modulation Systems—Part 1: Earth Stations and Spacecraft (Blue Book, Issue 32), released October 2021.