text: Chapter 5
  post, or as a center for liaison with combat forces (see DOD Law of War Manual, 7.17.1.1). However, the
  fact that sick or wounded members of the armed forces are being cared for in these hospitals, or the presence
  in these hospitals of small arms and ammunition taken from such combatants and not yet handed to the proper
  service, are not to be considered acts harmful to the enemy (GC art. 19).
  5-42. Protection for civilian hospitals may, however, cease only after due warning has been given, naming
  in all appropriate cases a reasonable time, and after such warning has remained unheeded (GC art. 19;
  consider AP I art. 13). The obligation to refrain from the use of force against a civilian hospital acting in
  violation of its mission and protected status without due warning does not prohibit the exercise of the right
  of self-defense (see DOD Law of War Manual, 7.17.1.2).
  5-43. States that are parties to a conflict must provide all civilian hospitals with certificates showing that
  they are civilian hospitals and that the buildings they occupy are not used for any purpose that would deprive
  these hospitals of protection in accordance with Article 19 of the GC. They must also be marked with the
  appropriate distinctive emblem provided for in Article 38 of the GWS (as described in paragraph 4-30), but
  only if authorized by the State. The parties to the conflict must, in so far as military considerations permit,
  take the necessary steps to make the distinctive emblems indicating civilian hospitals in a manner clearly
  visible to the enemy land, air, and naval opposing forces in order to obviate the possibility of any hostile
  action (see also figure 4-1, page 4-8). In view of the dangers to which civilian hospitals may be exposed by
  being close to military objectives, it is recommended that such hospitals be located as far as possible from
  military objectives (GC art. 18).
  Civilian Medical Personnel
  5-44. Persons regularly and solely engaged in the operation and administration of civilian hospitals—
  including the persons engaged in the search for, removal, transport of, and care for wounded and sick
  civilians, the infirm, and maternity cases—must be respected and protected by State parties to the conflict
  (GC art. 20). In occupied territory and in zones of military operations, such persons must be recognizable by
  means of an identity card certifying their status, bearing the photograph of the holder, and embossed with the
  stamp of the responsible authority, and also by means of a stamped, water-resistant armlet that they must
  wear on the left arm while carrying out their duties. This armlet must be issued by the State with control over
  such persons and shall bear the Red Cross, Red Crescent, or Red Crystal, as applicable (GC art. 20).
  Medical Transport
  5-45. Means of transport, including vehicles, convoys, and hospital trains, must be respected and protected
  in the same manner as hospitals as long as they are exclusively engaged in the transport of wounded and sick
  civilians; they must be appropriately marked (GC art. 21, 22; consider AP I art. 21). Civilian medical aircraft
  are subject to the same restrictions as military medical aircraft, and should be respected and protected when
  recognized as such (GC art. 22; consider AP I art. 24-28).
  Consignments of Medical Supplies, Food, and Clothing
  5-46. Parties to the conflict must allow the free passage of all consignments of medical and hospital stores
  and objects necessary for religious worship for civilians of another State, even if that State is an opposing
  party. Parties to the conflict must also permit the free passage of consignments of essential food, clothing,
  and medicine intended for children under 15 years of age, expectant mothers, and maternity cases. A State
  Party’s obligation to allow free passage is subject to the condition that State Party is satisfied that there are
  no serious reasons to fear: (1) that the consignments may be diverted from their destination; (2) that the
  control may not be effective; or (3) that a definite advantage may accrue to the military efforts or economy
  of the enemy through the substitution of the above consignments for goods which would otherwise be
  provided or produced by the enemy or through the release of such material, services, or facilities as would
  otherwise be required for production of such goods. Technical arrangements may be negotiated with the
  opposing side to facilitate such passage (GC art. 23).