Related Rule
Australia
Practice Relating to Rule 63. Use of Flags or Military Emblems, Insignia or Uniforms of Neutral or Other States Not Party to the Conflict
Australia’s Commanders’ Guide (1994) states: “It is prohibited to use flags, military emblems, insignia or uniforms of neutral or other States not party to the conflict.” 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 904.
The Guide further specifies:
The clothing of neutral nations must never be worn by the forces of a belligerent. Nor should flags, symbols and military markings of a neutral nation be used by a belligerent. While naval ships may use such markings in operations that do not involve actual combat, no similar rule applies to military aircraft or land operations. 
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 510.
Australia’s Defence Force Manual (1994) provides: “In armed conflict, it is prohibited to use flags, military emblems, insignia or uniforms of neutral or other nations not party to the conflict.” 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 705.
Australia’s LOAC Manual (2006) states: “In armed conflict it is prohibited to use flags, military emblems, insignia or uniforms of neutral or other nations not party to the conflict.” 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 7.6.
The LOAC Manual (2006) replaces both the Defence Force Manual (1994) and the Commanders’ Guide (1994).
Australia’s Geneva Conventions Act (1957), as amended in 2002, provides:
A person shall not, without the consent in writing of the Minister or of a person authorized in writing by the Minister to give consents … use for any purpose whatsoever any of the following:
(f) such … emblems, identity cards, signs, signals, insignia or uniforms as are prescribed for the purpose of giving effect to [the 1977 Additional Protocol I]. 
Australia, Geneva Conventions Act, 1957, as amended in 2002, Section 15(1)(f).
The war crimes provisions in this Act were removed in 2002 and incorporated into the Criminal Code Act (1995).
Australia’s Geneva Conventions Act (1957), as amended in 2009, states:
Subject to this section, a person shall not, without the consent in writing of the Minister or of a person authorized in writing by the Minister to give consents under this section, use for any purpose whatsoever any of the following:
(f) such other emblems, identity cards, signs, signals, insignia or uniforms as are prescribed for the purpose of giving effect to [the 1977 Additional] Protocol I or [the 2005 Additional] Protocol III. 
Australia, Geneva Conventions Act, 1957, as amended in 2009, § 15(1)(f).