# Council Decision of 23 September 2013 on the security rules for protecting EU classified information (2013/488/EU), Division 17: Secured Areas protected against eavesdropping shall be designated technically Secured Areas. The following additional requirements shall apply:

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

(a) such areas shall be IDS equipped, be locked when not occupied and be guarded when occupied. Any keys shall be controlled in accordance with Section VI;
(b) all persons and material entering such areas shall be controlled;
(c) such areas shall be regularly physically and/or technically inspected as required by the competent security authority. Such inspections shall also be conducted following any unauthorised entry or suspicion of such entry; and
(d) such areas shall be free of unauthorised communication lines, unauthorised telephones or other unauthorised communication devices and electrical or electronic equipment.

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Source: https://www.legislation.gov.uk/eudn/2013/488/annex/II/division/IV/division/17 (the official version)
Page: https://openlegislation.uk/eu-decision-2013-488/annex-II/division-IV/division-17
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.