is what it stands for, if you feel you must expand the acronym

Security, Normalisation and Conservation Criteria
The document Security, Normalisation and Conservation Criteria for
Applications Used for the Exercise of Powers , prepared by the Higher
Council for Information Technology and for Electronic Administration,
states in Chapter 6, Free, Open Source Software (Section 6.1):
“Open source programs and applications should be adopted in
environments where solutions of this type, which satisfy the needs and
requirements of the application or information to be conserved, are
possible. Specifically, the overall offer of available software distributed
according to various types of licenses should be taken into
consideration in acquiring products or development of custom-made
software and technical and economic rationality criteria should be
applied. Thus, all possible alternatives in the framework of the
legitimate obligations and interests of the Government will be
evaluated, independently of the acquisition procedures
applicable in each case.”

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Note added at 2 hrs (2018-11-21 18:22:54 GMT)
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los Criterios de seguridad, normalización y conservación (Criterios SNC) tienen como triple objetivo:

Proporcionar el conjunto de medidas organizativas y técnicas (seguridad, normalización, conservación) que garanticen el cumplimiento de los requisitos legales para la validez y eficacia de los procedimientos administrativos de la Administración General del Estado, que utilicen los medios electrónicos, informáticos y telemáticos en el ejercicio de sus potestades.