diff --git a/jmsfx-generator/pom.xml b/jmsfx-generator/pom.xml
index 23f315a6..2cf3d4ce 100644
--- a/jmsfx-generator/pom.xml
+++ b/jmsfx-generator/pom.xml
@@ -115,9 +115,19 @@
diff --git a/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60200200.svg b/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60200200.svg
index 218a6376..bdcb100a 100644
--- a/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60200200.svg
+++ b/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60200200.svg
@@ -1,23 +1,41 @@
diff --git a/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60210100.svg b/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60210100.svg
index 4a4ab5aa..f1838338 100644
--- a/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60210100.svg
+++ b/jmsfx-standard/src/main/resources/svg/Appendices/Cyberspace/60210100.svg
@@ -1,17 +1,39 @@
diff --git a/jmsfx-standard/src/main/resources/svg/README.md b/jmsfx-standard/src/main/resources/svg/README.md
index 39f096ef..26f123f2 100644
--- a/jmsfx-standard/src/main/resources/svg/README.md
+++ b/jmsfx-standard/src/main/resources/svg/README.md
@@ -47,7 +47,36 @@ For symbol assembly purposes, the following SIDC positions are used to determine
## Details
-This section describes the details of the internal composition of the SVG files, for those developers who wish to make their own changes (TBD).
+This section describes the details of the internal composition of the SVG files, for those developers who
+wish to make their own changes.
+
+### Free canvas icons
+
+The Control Measure fragments, and three of the Cyberspace ones, are `FREE_CANVAS`: GIS construction samples
+showing how a measure is drawn on a map, rather than icons composed into a symbol. APP-6E 8.1.3 exempts them
+from the composition rules. They carry illustrative material alongside the drawn content, so each one holds:
+
+| element | how many | what it is |
+| --- | --- | --- |
+| `` | exactly one | the content - what a consumer renders |
+| `` | zero or one | the construction guide: anchor point labels (`T`, `AS`) and the `PT 1`/`PT 2` arrows that place them |
+| `` | zero or more | a worked sample, normally `display="none"`. Where there is more than one they are numbered `example1`, `example2` and so on |
+| `` | as needed | anything `main` references. Patterns and markers belong here, never loose in the document or inside `main` |
+
+The template is optional because two kinds of fragment have nothing to construct:
+
+* An **area** is defined by at least three control points the user places, so there is no fixed geometry a
+ template could draw. That covers every area measure without one, including Airhead Line, which is an area
+ despite the name.
+* The **Space Debris** fragments are whole symbols in the way an ordinary icon is, so `main` holds all of it.
+
+Nothing outside that list appears at the root of a free canvas fragment: no bare drawing elements, and no
+groups under any other name.
+
+### Everything else
+
+Every other fragment holds a single content group, named for what it is - `frame`, `main`, `echelon`, `mod1`,
+`mod2`. Those names are not yet consistent across the tree; making them so is tracked separately.
## Licensing