Règle correspondante
Practice Relating to Rule 1. The Principle of Distinction between Civilians and Combatants
Section A. The principle of distinction
Spain’s LOAC Manual (2007) states that “a distinction must be made between civilians and combatants”. 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 3.1.a.
Spain’s Royal Ordinances for the Armed Forces (2009) states: “In the conduct of any operation, [members of the armed forces] must take into account the principle of distinction between civilians and combatants … in order to protect the civilian population.” 
Spain, Royal Ordinances for the Armed Forces, 2009, Article 111.
In 2010, in the Couso case, which concerned the killing of a Spanish journalist in Baghdad on 8 April 2003 by troops of the United States of America, the Criminal Chamber of Spain’s Supreme Court referred to norms of IHL relevant to the case under review, including Article 48 of the 1977 Additional Protocol I. 
Spain, Supreme Court, Couso case, Judgment, 13 July 2010, Section II(II), Sexto, § 2, p. 13.
In 2010, in its report to the UN General Assembly on the status of the 1977 Additional Protocols, Spain stated:
Article 85 entitled “Principle of Humanity”, contained in Title IV on Operations [of the Royal Ordinances for the Armed Forces (2009)] clearly embodies the spirit of the [1949] Geneva Convention and its [1977] Additional Protocols, as it provides that “[the] … conduct [of members of the armed forces] in any conflict or military operation must conform to the applicable rules of the international treaties on international humanitarian law to which Spain is a party”.
That is further developed in Chapter VI on Ethics in Operations, which goes into specific duties under international humanitarian law … the principle of the distinction between civilians and combatants. 
Spain, Report on the Status of the Protocols Additional to the Geneva Conventions of 1949 and relating to the protection of victims of armed conflict, 5 May 2010, Section 2.