What it is
STANAG 6503 is the NATO Standardization Agreement by which participating nations commit to implement AGeoP-14, Edition A, the Allied Publication that "defines the implementation of DMGEM by specifying the structure of AML+ Product Specifications." This is Edition 1, promulgated 12 May 2017, and the cover states plainly that "this STANAG does not supersede any document." The STANAG itself carries no technical content: participating nations "agree to implement the following standard," and the standard named is AGeoP-14 - anyone working directly with DMGEM's data products needs that publication, not this cover agreement.
What DMGEM covers, and what it does not adopt
DMGEM, the Defence Maritime Geospatial Exchange Model, "addresses the interoperability requirements specific to geospatial information in the maritime environment." It complements the NATO Geospatial Information Framework (NGIF), reflects NATO Geospatial Policy MC 0296, and "mitigates geospatial deficiencies identified in the NATO Geospatial Deficiencies Matrix (NGDM)." Once implemented, AGeoP-14 "provides the framework for AML+ Product Specifications which define data products for use across WECDIS and C2 environments," and STANAG 7170 already "meets this requirement for existing Additional Military Layers (AML) specifications."
The cover is explicit about where DMGEM sits next to civil geospatial standards: "the civilian International Hydrographic Organization (IHO) community is moving towards a more contemporary and flexible environment using the S-100 standard," while "in parallel NATO is developing the NGIF within which AML+ products will also exist." STANAG 6503 does not adopt S-100 as a NATO standard. What it commits to is a "defined mapping (crosswalk) between S-100 and NGIF data models," and to using "existing registers managed by the IHO and DGIWG" that already sit alongside the civil hydrographic community's own infrastructure.
Who ratifies it, and how it binds
STANAG 6503 binds nations, not suppliers. Nations are "invited to examine their ratification of the STANAG" and to advise the NSO of their intention regarding its implementation, and "the national responses are recorded in the NATO Standardization Document Database (NSDD)." It "is effective upon receipt" for the nations and NATO bodies that have ratified it, and partner nations are separately "invited to adopt this STANAG." Implementation is a further step, complete when "all parties must be capable of using AML+ to provide geospatial products and services in support of NATO operations in the maritime domain." Nations report their effective implementation "using the form in Annex H to AAP-03(J)"; partner nations report adoption "using the form in Annex G to AAP-03(J)." The STANAG "is to be reviewed at least once every three years."
How it is evaluated
STANAG 6503 describes no certification scheme and no third-party audit. What it describes is nations reporting their ratification and implementation status to NATO, recorded in the NSDD. Where a contractor's geospatial data work does get checked in practice, the assessor and the evidence expected are set by the contract's own quality clause and by AGeoP-14 itself, not by this STANAG.
Standards it references
STANAG 6503 covers AGeoP-14, the Allied Publication that carries DMGEM's actual product specifications. Its "Other Related Documents" list five further STANAG/Allied Publication pairs: STANAG 7170, which covers AGeoP-19 (Additional Military Layers digital geospatial data products); STANAG 1116, which covers AMP-11 (naval mine warfare information and data transfer); STANAG 2211, which covers AGeoP-21 (geodetic datums, projections, grids and grid references); STANAG 2251, which covers AGeoP-17 (scope and presentation of military geographic information and documentation); and STANAG 2592, which covers AGeoP-11 (the NATO Geospatial Information Framework). STANAG 2586, which covers AGeoP-8 (the NATO Geospatial Metadata Profile), is also named. Nations report their ratification, implementation and adoption of STANAG 6503 under AAP-03.