1
Source of Control Reference. The number assigned by a design control manufacturer of an end item of equipment, including a Government activity, to a drawing that restricts procurement (1) to the specified item(s) described on the drawing and (2) to the stated source(s) of supply designated thereon. These restrictions are imposed on the cognizant design activity to ensure procurement of the only item(s) known as the result of test or evaluation to be satisfactory for the stated critical application. Includes only those drawings which meet the definition for source Control Drawing in MIL-STD-100. (Applicable only to type 1, 1B, 2, 4, and 4B item identifications.)

2
Definitive Government Specification or Standard Designator Reference. A part number, style number, or type designator included in or developed in accordance with a Government specification or standard which has the effect of fully identifying an item of supply. This code shall also be used for a Government specification or standard which, although not including part numbers, style numbers, or type designators, covers a single item of supply. These reference numbers may be coded with Reference Number Variation Code (RNVC) 1 in accordance with volume 2, paragraph 2.9.2.n.(4).

(Nondefinitive Government specifications, or standard designator references shall be coded 4; specification control drawings as defined in MIL-STD-100 shall be coded 7; professional association or standard designator references shall be coded 3.)

3
Design Control Reference. The primary number used identify an item of production or a range of items of production, by the manufacturer (individual, company, firm, corporation, or Government activity) which controls the design, characteristics, and production of the item by means of its engineering drawings, specifications and inspection requirements.

4
Nondefinitive U.S. Government Specification or Standard Reference. Any Government specification or standard reference other than those indicated in code 2 as definitive references. This code shall be used for nondefinitive Government specifications and standard references and nondefinitive part numbers, type designators, and style numbers included therein which are coded with RNVC 1

(Includes the specification number of those specifications for which type designation is used as code 2. Excludes professional association, industrial association, or manufacturer's specification or standard reference which shall be code 3, and specification control drawings as defined in MIL-STD-100 which shall be coded 7)

5
Secondary Reference. Any additional number, other than a primary number (codes 1, 2, 3, 4), informative reference (code 6) or specification control reference (code 7) assigned to an item of production or supply by a commercial or Government organization, which represents the same item of production or supply to which the National Stock Number (NSN) was assigned. The reference number may have has an RNCC or 1, 2, 3, 4, or 7 but has since been replaced in the item-of-supply concept of the NSN by another primary number.

Includes additional numbers assigned by the design control organization; superseded or canceled specification; superseded or discontinued reference numbers which may have resulted from: a manufacturer's change in numbering system;; the manufacturer no longer produces the item or is no longer a technically approved source; the manufacturer or supplier for that number is out of business.

(Obsolete, superseded, canceled, or discontinued reference numbers coded RNCC 5 shall be coded Reference Number Variation Code 9. All secondary reference Extra Long Reference Numbers (ELRNs), whether current, obsolete, superseded, canceled, or discontinued, shall be coded RNCC 5 and RNVC 1.)

6.
Informative Reference. North Atlantic Treaty Organization (NATO) Stock Numbers (CAGEC 99995), Production Equipment Codes (CAGEC 99998), and DoD Ammunition Codes (CAGEC 99999) which may be related to NSNs. (Reference numbers for the CAGECs cited above shall be coded RNVC 9.)

7
Vendor Item Drawing Reference (formerly Specification Control Reference. The number assigned by a design activity to a drawing that is not item identifying, but which delineates existing commercial or vendor developed items meeting all engineering and test requirements specified, without imposing additional test/engineering requirements not normally provided by the Vendor(s). Includes only those drawings which meet the definition of Vendor Item Drawing in MIL-STD 100. Vendor Item Drawing References are administrative control numbers and shall not be used as part identification numbers.

8
U.S./NATO-Reproduced Item Identification Number. A number representing a reproduction of an item of production by a NATO country (including the United States) for which authorization to use the NATO/National Stock Number has been granted by the origination country. The reproduced item represents the same item of reproduction as the original item.

A
Design Category Packaging and Related Logistics Data Reference Number. The number of a document representing packaging and related logistics data requirements.

B
Non-design Category Packaging and Related Logistics Data Reference Number. The number of a military standard and applicable standard designation decoded in the standard publication.

C
Advisory Reference. A number assigned to an item of production or supply not included in the item-of-supply concept to which the NSN has been assigned (e.g., an item that may have been used in the preproduction equipment design which has since been redesigned or replaced). Use of this RNCC is restricted to conditions where cross-reference is required to establish identification to an item of supply. Additional, there is no direct relationship of the reference number to the NSN other than a Service/Agency individual decision, (RNCC C shall be used only in conjunction with RNVC 1.)

D
Drawing Number Reference. A number assigned by a design activity to a drawing or the technical documentation which identifies a drawing/document that is related to an item of supply or production but does not qualify for assignment of codes 1, 3, 5, 7, or C. Code D reference numbers will not be used in item-of-supply determinations.

NOTES:

1. Each reference number or portion of a reference number shall be coded to indicate the relationship of the reference number to the item of supply.

2. When determination cannot be made as to whether or not a reference number is the design control reference it shall be considered the design control reference until positive determination can be made. However, only one reference number shall be considered as the design control reference for each type 1A, 1B, 4A, or 4B Federal item Identification. In addition, only one reference number shall be considered as the design control reference for each item of production included in the concept of a type 1, type 2, or type 4 FII.

3. The following reference number action (additions, deletions, or changes) shall be collaborated:

All actions against (1) source control reference, (2) definitive Government specifications or standard designator reference, (3) design control reference, (4) nondefinitive Government specification/standard reference, (5) specification control references, and (6) related item-of-production references.

All actions to change RNCC 4 (nondefinitive specification or standard reference) to RNCC 2 (definitive Government specification or standard designator reference); or the change or RNCC 5 (secondary reference) to RNCC 1 (source control reference), RNCC 3 (design control reference), or RNCC 7 (specification control reference).

4. Reference numbers assigned RNCC D will always be submitted with RNVC 9.

5. Inasmuch as the use of RNCC C is a Service/Agency individual decision, the same reference number may be recorded for more than one NSN.