Related Rule
Spain
Practice Relating to Rule 12. Definition of Indiscriminate Attacks
Section C. Attacks whose effects cannot be limited as required by international humanitarian law
Spain’s LOAC Manual (1996) states: “Prohibited indiscriminate attacks are: … those which employ a method or means of combat the effect of which cannot be limited as required by [the 1977 Additional Protocol I].” 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, División de Operaciones, 18 March 1996, Vol. I, § 4.4.c.
Spain’s LOAC Manual (2007) includes in its definition of indiscriminate attacks: “attacks that employ a method or means of combat that has effects that cannot be limited”. 
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, § 4.4.c.
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 51(4)(c) of the 1977 Additional Protocol I. 
Spain, Supreme Court, Couso case, Judgment, 13 July 2010, Section II(II), Sexto, § 2, p. 14.