The recommendation includes two annexes to aid in implementation.

• Annex A – Examples of CRC implementations using shift registers: This section provides reference logic circuit diagrams for generating the CRC-4, CRC-5, and CRC-6 values. These serve as a practical guide for hardware and software engineers designing equipment that conforms to the standard.
• Annex B – Alphabetical list of abbreviations used in this Recommendation: A glossary defining key acronyms such as AIS (Alarm Indication Signal), CRC (Cyclic Redundancy Check), FAS (Frame Alignment Signal), LFA (Loss of Frame Alignment), SMF (Sub-Multiframe), and SSU (Synchronization Supply Unit).