What it is
STANAG 3109 is the NATO standardization agreement covering symbol marking of aircraft servicing and safety/hazard points. Like every STANAG, it is not itself a technical specification: it is the agreement by which NATO nations commit to implement one, and the specification lives in the Allied Publication it covers, here AASSEP-03, Edition A. Participating nations "agree to implement the following standard for symbol marking of aircraft servicing and safety/hazard points" - that standard, not the STANAG's own text, is what actually defines the markings. This is the sixth edition, dated 15 September 2014, superseding an earlier edition of STANAG 3109.
Why the agreement exists
The stated aim is interoperability. The STANAG exists "to standardize servicing markings on aircraft for cross-servicing and to give warnings, the neglect of which may cause damage to equipment or injury to personnel." In plain terms: when ground crews from different nations service or cross-service each other's aircraft, they need to recognise the same markings for servicing and safety/hazard points, or the risk is damage to the aircraft or injury to the people working on it. The STANAG does not describe what those markings look like; that detail belongs to AASSEP-03.
How it binds a nation, and reaches a supplier
Ratification and implementation are separate steps here. The STANAG is "effective upon receipt and ready to be used by the implementing nations and NATO bodies" once ratified, but a nation is only considered to have implemented it "when the provisions specified therein have been included in the national documentation concerned with reference to STANAG 3109." Partner nations sit outside ratification altogether: they "are invited to adopt this STANAG" rather than being bound by it. So "is STANAG 3109 mandatory" has no single answer - it depends on ratification, national documentation, and whether a contract or tender then invokes it. For an aircraft servicing organisation, that route is how the obligation actually arrives; the STANAG itself binds nations, not companies.
Reporting, review and supervision
Nations record their ratification and implementation decisions with the NATO Standardization Office (NSO), in the NATO Standardization Document Database (NSDD). A nation reports its effective implementation using the form in Annex H to AAP-03(J); a partner nation uses Annex G of the same publication to report adoption. The STANAG "is to be reviewed at least once every three years", with the result recorded in the NSDD, and a nation or NATO body can propose a change at any time to the tasking authority for the next review. The agreement is unclassified, handled under C-M(2002)60, and is not for commercial reproduction or sale without the publisher's permission, though member nations, Partnership for Peace countries, and NATO commands and bodies are exempted.
What it does not cover
The STANAG names two other documents covering related ground without stating whether either binds alongside it: ISO 1950 (Aircraft - Identification of Servicing, Maintenance, Ground Handling and Safety/Hazard Points) and ISO 3864 (Graphical symbols - Safety colours and safety signs). Both sit outside our catalogue. The marking specification itself - what the symbols look like, where they go, what they mean - is entirely in AASSEP-03, not here.
How you are evaluated
No organisation is certified against STANAG 3109. What the document describes is a national reporting and periodic-review cycle: a nation's ratification and implementation decision is recorded with the NSO, effective implementation is reported on a standard NSDD form, and the STANAG is reviewed at least every three years. There is no accredited body, notified body or third-party audit anywhere in this mechanism, and nothing in it is assessed against a company directly.