Règle correspondante
Sweden
Practice Relating to Rule 58. Improper Use of the White Flag of Truce
Sweden’s IHL Manual (1991) considers that the prohibition of improper use of recognized emblems, as contained in Article 38 of the 1977 Additional Protocol I, is part of customary international law. 
Sweden, International Humanitarian Law in Armed Conflict, with reference to the Swedish Total Defence System, Swedish Ministry of Defence, January 1991, Section 2.2.3, p. 19.
The manual adds:
In land combat it is not unusual for one of the parties to attempt to win a tactical advantage by concealing the character of his own forces prior to attack, in order to mislead or surprise the adversary … A flag of truce may not, however, be used for such purposes. 
Sweden, International Humanitarian Law in Armed Conflict, with reference to the Swedish Total Defence System, Swedish Ministry of Defence, January 1991, Section 3.2.1.1.b, p. 30.
Under Sweden’s Penal Code (1962), as amended in 1998, “misuse of … the flag of parlementaires” constitutes a crime against international law. 
Sweden, Penal Code, 1962, as amended in 1998, Chapter 22, § 6(2).