ARINC 429 defines the most-widely used data transfer method used within and among avionics systems. It specifies the physical data bus, the electrical characteristics, and the data word formats. Supplement is 18 is a routine update that assigns new ARINC 429 labels, equipment IDs, and System Address Labels (SAL). The document is a re-mastering to bring it up-to-date with the latest ARINC Standard formats and styles.