employed, under competent orders, in the transportation and protection of the convoy.
The obligation to return the sanitary matériel, as provided for in article 14, shall apply to railway trains and vessels intended for interior navigation which have been especially equipped for evacuation purposes, as well as to the ordinary vehicles, trains, and vessels which belong to the sanitary service.
Military vehicles, with their teams, other than those belonging to the sanitary service, may be captured.
The civil personnel and the various means of transportation obtained by requisition, including railway matériel and vessels utilized for convoys, are subject to the general rules of international law.
Chapter VI. Distinctive emblem
Art. 18
Out of respect to Switzerland the heraldic emblem of the red cross on a white ground, formed by the reversal of the federal colors, is continued as the emblem and distinctive sign of the sanitary service of armies.
Art. 19
This emblem appears on flags and brassards as well as upon all matériel appertaining to the sanitary service, with the permission of the competent military authority.
Art. 20
The personnel protected in virtue of the first paragraph of article 9, and articles 10 and 11, will wear attached to the left arm a brassard bearing a red cross on a white ground, which will be issued and stamped by competent military authority, and accompanied by a certificate of identity in the case of persons attached to the sanitary service of armies who do not have military uniform.
Art. 21
The distinctive flag of the convention can only be displayed over the sanitary formations and establishments which the convention provides shall be respected, and with the consent of the military authorities. It shall be accompanied by the national flag of the belligerent to whose service the formation or establishment is attached.
Sanitary formations which have fallen into the power of the enemy, however, shall fly no other flag than that of the Red Cross so long as they continue in that situation.
Art. 22
The sanitary formations of neutral countries which, under the conditions set forth in article 11, have been authorized to render their services, shall fly, with the flag of the convention, the national flag of the belligerent to which
