# Commission Implementing Regulation (EU) 2019/123 of 24 January 2019 laying down detailed rules for the implementation of air traffic management (ATM) network functions and repealing Commission Regulation (EU) No 677/2011 (Text with EEA relevance), Division 2: The CAA must provide the Network Manager with the following data and information within agreed timescales ... to support the provision of the network function for SSR transponder codes:

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

(a)an up-to-date record of the allocation and use of all SSR transponder codes within their area of responsibility, subject to any security constraints concerning full disclosure of specific military code allocations not used for general air traffic;
(b)justification to demonstrate that existing and requested allocations of SSR transponder codes are the minimum necessary to meet operational requirements;
(c)details of any allocations of SSR transponder codes that are no longer operationally required and that can be released for re-allocation within the network;
(d)reports of any actual unplanned shortfall in SSR transponder code allocations;
(e)details of any change in the installation planning or in the operational status of systems or constituents that may impact on the assignment of SSR transponder codes to flights.

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Source: https://www.legislation.gov.uk/eur/2019/123/annex/IV/part/C/division/1/division/2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2019-123/annex-IV/part-C/division-1/division-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.