A short primer on the parts of a military symbol and the words this site uses for them, enough to make the Generate page make sense. It is an introduction, not a substitute for the standard itself.

This site follows NATO APP-6, Edition E (2023). It is related to, and largely converged with, the US MIL-STD-2525D, but the two are separate documents and differ in detail.

The parts

A symbol is a composition of a frame, a fill, an icon, modifiers and amplifiers, arranged within and around a bounding octagon. Between them they say what the object is, whose it is, and what state it is in.

The frame

The frame is the border of the symbol, and the base that everything else is added to. Its shape carries three things at once:

Standard identity

Your relationship to the object: Pending, Unknown, Friend, Neutral, Hostile, Assumed Friend or Suspect. This is also what the frame's colour reflects.

Dimension

Broadly, where the object operates. A closed frame denotes Land and Sea Surface, a frame open at the bottom denotes Air and Space, and a frame open at the top denotes Sea Subsurface.

Status

Whether the object is actually there, or only anticipated.

The line style carries identity and status together, and there are three of them:

• Solid - present or confirmed.
• Dashed - anticipated, planned or suspected.
• Dotted - the identity itself is uncertain, as with Pending, Assumed Friend and Suspect.

The third overrides the others: when identity is uncertain the frame is dotted, and status is simply not shown.

Dimensions and symbol sets are not the same thing

A dimension is broadly the environment an object operates in - Air, Space, Land, Sea Surface, Sea Subsurface. Some have no physical environment at all: Activity, Unknown, Dismounted Individual and Cyberspace count as dimensions regardless.

A symbol set is narrower. Each dimension is made up of one or more symbol sets - the Air dimension covers both Air and Air Missile, for instance, and Cyberspace covers a whole family of them. That is why this site offers 23 symbol sets where the standard illustrates far fewer dimensions, and why Land Equipment and Sea Surface share a frame shape despite being different symbol sets in different dimensions.

It is the symbol set you pick first on Generate, and the symbol set that the leading path segment names in the API - /Air, /LandUnits, /SeaSurface. Within one, symbols narrow by entity, then entity type, then entity sub-type.

Modifiers and amplifiers are not the same thing

The two are easy to confuse, and the distinction is simply where they go.

A modifier qualifies the icon and sits with it, inside the bounding octagon - above, below or beside the main icon. There are two slots, sector one and sector two.

Edition E introduced common modifiers. Previously, a modifier that applied to several symbol sets had to be defined separately in each of them, which both duplicated the work and consumed capacity - each sector allows only three digits, so the space is genuinely limited. Those shared modifiers are now defined once and are available to every symbol set.

So the modifiers you can actually use on a symbol are the union of two sets: the common modifiers, plus whatever that particular symbol set defines for itself. That is exactly what the dropdowns on Generate offer, and why the list changes when you switch symbol set while some entries stay put.

An amplifier is optional extra information and is displayed outside the frame - echelon, a unit designation, a date-time, and so on. Not every amplifier applies to every dimension, and the standard is explicit that only the minimum necessary should be shown, since they clutter quickly.

The SIDC

All of the above has a code. A symbol identification code, or SIDC, is a 30-position hexadecimal string - thirteen elements of information, written as three sets of ten. It is the entire symbol reduced to a key. Taking one apart:

1403100214

Version, context, standard identity, symbol set, status, the headquarters / task force / dummy indicator, and an amplifier - here a present, real-world, friendly Land Unit headquarters at platoon echelon.

1204010006

Entity, entity type, entity sub-type, then the sector one and sector two modifiers - movement and manoeuvre, narrowing to anti-armour, narrowing to armoured, with no sector one modifier.

0100000000

For each sector, whether its modifier comes from the symbol set or from the common table; then further amplifiers and a country code.

Two details in there are worth drawing out, because both are consequences of how tight the code is.

The first is how common modifiers fit. A symbol set's own modifier gets two digits, but a common modifier needs three - and there was no room to widen the code. So the third digit was borrowed from the last set of ten: read digit 22 first, then digits 19 and 20, and the example's 1 and 06 give 106, high mobility / off-road. A zero in that leading position means the modifier is the symbol set's own after all.

The second is that the seven standard identities collapse into four standard identity groups - Unknown covers Pending and Unknown, Friend covers Friend and Assumed Friend, Neutral stands alone, and Hostile covers Hostile and Suspect. Where a part of a symbol varies by frame shape, it is the group that selects which SVG to use, not the identity: four frame shapes, so four variants, not seven.

Which is the point of the whole thing. Given a SIDC, every SVG that makes up the symbol is determined - the code is read, not interpreted. The desktop Icon Creator shows the code as you build a symbol, in the same three groups of ten.

How they are drawn here

Every part is drawn against the same 612 x 792 canvas, each occupying its own region of it. Nothing is positioned relative to anything else - the shared coordinate space is what makes the pieces line up. Composing a symbol is therefore a matter of choosing the right SVG for each part and layering them in a fixed order:

frame
  status
    headquarters / task force / dummy
      main icon
        amplifiers
          sector one modifier
            sector two modifier

Built up a piece at a time

The same Air symbol, narrowed one step at a time. Each is a live URL from this site.

	/Air/symbol The bare frame - an air object of unknown identity.
	/Air/symbol/entity/MILITARY Narrowed to a military entity.
	/Air/symbol/FIXED_WING An entity type - fixed-wing.
	/Air/symbol/FIXED_WING/BOMBER A sub-type - bomber.
	/Air/symbol?sectorOneMod=FIGHTER A sector one modifier, on the bare frame.

Use Browse to see what a symbol set contains, and Generate to build one.

Source

NATO Standard APP-06, NATO Joint Military Symbology, Edition E, Version 1, October 2023. Allied Procedural Publication, published by the NATO Standardization Office; promulgated 11 October 2023, superseding Edition D, Version 1. The agreement of nations to use it is recorded in STANAG 2019.

No stable public link is given here deliberately - NATO does not publish one that reliably survives, so the full title, edition and STANAG number are more use for tracking down the document than a URL that may already have moved. The descriptions above are written from it rather than reproduced from it.