MIL-STD-1686C states
"Equipment containing ESDS parts and assemblies shall be marked with the EIA RS-471 symbol*. The symbol shall be located on the exterior surface of the equipment and readily visible to personnel prior to gaining access to ESDS parts and assemblies within the equipment. The following ESD caution statement should be placed adjacent to the RS-471 symbol: "CAUTION, CONTAINS PARTS AND ASSEMBLIES SUSCEPTIBLE TO DAMAGE BY ELECTROSTATIC DISCHARGE (ESD)."
* Note: EIA RS-471 symbol and ESD Association symbol outlined in ESD S 8.1, Figure 1A, the ESD susceptibility symbol are the same symbol.
Per ESD Handbook TR20.20 states Marking of Assemblies and Equipment "Marking of hardware items (assemblies and equipment) can be accomplished by using the [susceptibility] symbol. Military organizations sometimes use MIL-STD-1285 for hardware marking and that document once required the use of the "three arrows in a circle" symbol. That symbol has been changed for consistency with industry marking to the "hand in triangle" symbol. Marking of hardware is dependent on space available on the item itself as well as the environment the item will operate in and whether marking will hinder the operation of the item. Some hardware labels might contain nomenclature along with the symbol. Wording such as, "Caution, contains assemblies susceptible to damage by electrostatic discharge (ESD)" may be included, again depending on available space." (Ref. section 5.3.14.1)