Stamped Out - Navy Nomenclature

The Nomenclature System

Navy MARK / MOD Nomenclature System
The United States Navy assigns MARK / MOD numbers to nearly all types of ordnance equipment not covered by their other designation systems. The MARK / MOD system has its origins in the early 1900’s but it was only formally adopted in 1944. It has been revised and expanded over time with the current standard defined in MIL-STD-1661.

Similar in concept to the Army Nomenclature System, the full nomenclature for an equipment item consists of an item name and the MARK / MOD numbers. Examples are:

KNIFE, FIGHTING, MARK 2
KNIFE, COMBAT W/SHEATH, MARK 3 MOD 0
KNIFE, DIVERS, MARK V

(1) This designates the military name of the item, this is always part of the complete nomenclature. According to MIL-STD-1661, the name is to precede the MARK number, and separated from the latter by a comma. The name should be selected from DoD Cataloging Handbook H6 ("Federal Item Name Directory") whenever possible. To ensure related items will be grouped together in all alphabetical listings the item names should be written in "inverted nomenclature." This is what leads to the typical "military speak" in which the usual order of words in the name is reversed.

(2) Is the actual MARK number. An arbitrary number typically used in progression but may jump within the equipment category. Skipped numbers may have been adopted and used but dropped in subsequent years so items in stock may not have a direct lineup ie MARK 1, MARK 2, MARK 3. The prefix EX instead of MARK is used for experimental items or previously adopted items under development. If and when an EX item is adopted for operational use, it will convert to a MARK designation, but will keep the assigned number in the proper placing. We could not find a standard on the use of Roman Numerals. They have been used in the past as we show in an example above, the Hard Hat Divers knives. The entire diving system as adopted in 1915 was known as the MARK V, the suit, helmet, shoes, knife, etc. The most current Navy Divers Manual currently lists the knife as a MK V so it is a current designation. We have seen the familiar Mark II so designated but again do not know if it is correct as the current rules we did find do not address it. Perhaps it was dropped many years ago?

(3) Is the MOD number, which indicates a modification of or to the original equipment. MOD numbers are assigned in numerical sequence for each modification or variation. The initial item being designated is always MOD 0 (Zero) but unless there is a follow up modification it is usually not written. If an item is approved from and experimental design the MOD number is started at the beginning from zero. Even if the experimental version was the fifth try as in MOD 5 if adopted as a MARK item it always reverts to zero.

The Navy rule is to write the words MARK and MOD unabbreviated and in uppercase when using the proper designation. With this said, abbreviations of MARK as MK and /or use of mixed-case (Mark/Mod) lettering is allowed. Dashes or other punctuation should never be used in any designator names, spaces are used in the designation unlike the Army system. All the following variants are correct nomenclature:

KNIFE, COMBAT, W/SHEATH, MARK 3 MOD 0
KNIFE, COMBAT, W/SHEATH, MK 3 MOD 0
KNIFE, COMBAT, W/SHEATH, Mark 3 Mod 0
KNIFE, COMBAT, W/SHEATH, Mk 3 Mod 0

The following versions do not conform to the rules of MIL-STD-1661, but are commonly seen in publication. This does not make it correct, it only shows that the proper specifications are not being followed.

KNIFE, COMBAT W/SHEATH, MARK-3 MOD 0
KNIFE, COMBAT W/SHEATH, MK- 3 MOD 0
KNIFE, COMBAT W/SHEATH, Mk. 3 MOD 0

The Nomenclature System

Odds N Ends