# Commission Implementing Regulation (EU) No 1207/2011 of 22 November 2011 laying down requirements for the performance and the interoperability of surveillance for the single European sky (Text with EEA relevance), Division 3: The following data items shall be made available to the transponder and be transmitted by the transponder via the Mode S protocol and in accordance with the formats specified in ICAO document 9871 (2nd edition):

Extent: E+W+S+N.I.

(a) 24-bit ICAO aircraft address;
(b) Mode A code;
(c) pressure altitude;
(d) flight status (on the ground or airborne);
(e) data link capability report;
airborne collision avoidance system (ACAS) capability,
Mode S specific services capability,
aircraft identification capability,
squitter capability,
surveillance identifier capability,
common usage Ground Initiated Comms.-B (GICB) capability report (indication of change),
Mode S subnetwork version number;
(f) common usage GICB capability report;
(g) aircraft identification;
(h) special position indication (SPI);
(i) emergency status (general emergency, no communications, unlawful interference) including the use of specific Mode A codes to indicate different emergency states;
(j) ACAS active resolution advisories when the aircraft is equipped with Traffic alert and collision avoidance system II (TCAS II).

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Source: https://www.legislation.gov.uk/eur/2011/1207/annex/II/part/1/division/3 (the official version)
Page: https://openlegislation.uk/eu-regulation-2011-1207/annex-II/part-1/division-3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.