Règle correspondante
Practice Relating to Rule 87. Humane Treatment
Section B. Civilians
Spain’s LOAC Manual (1996) provides that in occupied territory, “the Occupying Power shall treat the inhabitants humanely”. 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, Division de Operaciones, 18 March 1996, Vol. I, § 10.8.i.
Spain’s LOAC Manual (2007) states: “Treat all civilians … in your power with humanity”. 
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, § 5.5.b; see also § 10.3.e.(1).
Spain’s Royal Ordinances for the Armed Forces (2009) states that members of the armed forces “[m]ust treat … members of the civilian population that are in their power … humanely.” 
Spain, Royal Ordinances for the Armed Forces, 2009, Article 107.
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 protection of the … civilian population. 
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.