RECOMMENDATION ITU-R BS.643-2 - System for automatic tuning and other applications in FM radio receivers ...
ANNEX 1 - Specifications of the radio data system
1 Modulation of the data channel
2 Baseband coding
ANNEX 2 - Operational characteristics of the radio data system "RDS"
1 Compatibility with existing VHF/FM broadcasts
    1.1 Compatibility with the pilot-tone stereophonic main programme
    1.2 Compatibility with existing auxiliary signals
2 Reliability of reception of radio-data signals