Related Rule
Argentina
Practice Relating to Rule 137. Participation of Child Soldiers in Hostilities
III. Military Manuals
Argentina’s Law of War Manual (1989) provides: “The belligerent parties shall take all measures to ensure that children under the age of 15 do not participate directly in hostilities.” 
Argentina, Leyes de Guerra, PC-08-01, Público, Edición 1989, Estado Mayor Conjunto de las Fuerzas Armadas, aprobado por Resolución No. 489/89 del Ministerio de Defensa, 23 April 1990, § 4.12.
With respect to non-international armed conflicts in particular, the manual states: “Children under the age of 15 shall not … be authorized to participate in hostilities.” 
Argentina, Leyes de Guerra, PC-08-01, Público, Edición 1989, Estado Mayor Conjunto de las Fuerzas Armadas, aprobado por Resolución No. 489/89 del Ministerio de Defensa, 23 April 1990, § 7.04.
VI. Other National Practice
Upon ratification of the 1989 Convention on the Rights of the Child, Argentina stated that “it would have liked the Convention categorically to prohibit the use of children in armed conflicts”. 
Argentina, Reservations and declarations made upon ratification of the Convention on the Rights of the Child, 4 December 1990, reprinted in UN Doc. CRC/C/2/Rev.4, 28 July 1995, p. 12.