Research ยท Military message standards
COIE vs MTF-XML: running legacy and XML messaging side by side
Character-oriented messages and MTF-XML carry the same content in different syntax, and both will be in service together for years. The practical problem is converting between them without losing anything.
Two syntaxes for one message
Under Allied Data Publication 3 (ADatP-3), a message from the APP-11 catalogue can be carried in two ways: as slash-delimited text, Character-Oriented Information Exchange (COIE), or as XML, MTF-XML, with a one-to-one mapping between them. The slash-delimited form remains in use partly for its bandwidth advantage. A unit on one carrier and a unit on the other may need to exchange the same report.
What COIE looks like
A character-oriented message is a series of sets. Fields within a set are separated by slashes, and each set ends with a double slash. The meaning of a value comes from its position.
EXER/EXAMPLE//
MSGID/SITREP/EXAMPLE UNIT/001/SEP//
REF/A/DOC/EXAMPLE ORDER//<Message>
<Exercise>EXAMPLE</Exercise>
<MessageId>
<Type>SITREP</Type>
<Originator>EXAMPLE UNIT</Originator>
<Serial>001</Serial>
<Month>SEP</Month>
</MessageId>
</Message>What each is good at
| COIE (ADatP-3) | MTF-XML (APP-11) | |
|---|---|---|
| Structure | Positional, slash-delimited | Nested, named elements |
| Size | Compact | Larger, since names repeat |
| Validation | Written into each application | Against an XML schema, by standard tools |
| Reading it | Takes training | Names say what values are |
| Change | Every parser must be updated | Extensible, with namespaces |
Where conversion goes wrong
These are the places to test in any converter. Which of them applies depends on the message and the gateway.
- Delimiters inside free text. A slash in a remark can end a field early if it is not handled.
- Accented characters. Not every legacy path carries them, and French text is routine in Canadian traffic.
- Optional and repeating sets. Absent, empty and repeated need to stay distinct.
- Length and character limits. A value that fits in XML may not fit in the character-oriented form.
- Catalogue versions. Sender and receiver may be working from different editions of the message definitions.
Testing a round trip
Convert a message from one form to the other and back, then compare the two field by field. Build the corpus to include the awkward cases above: an empty optional set, a maximum-length value, an accented name, a slash in free text, a repeated group. A converter that only passes tidy examples has not been tested.
How Gridnorth approaches it
Gridnorth does not convert one syntax into the other. It holds one confirmed record and renders every form from it with deterministic code, so the two outputs cannot drift apart. It also parses character-oriented messages as input. The standards page states what has and has not been demonstrated. The authority for the definitions is the NATO Standardization Office.
Last reviewed September 29, 2026