diff --git a/AGENTS.md b/AGENTS.md
index 6c05dd1..c6a6372 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -40,6 +40,7 @@ In [docs/decisions.md](docs/decisions.md):
 - A change to what exists is a major; a minor only adds
 - Seeded output is promised within one version
 - An error is a contract by what it names, not its bytes
+- A format holding a reference is fenced at link, and its errors name its path
 - Raising the lowest supported Go is a major
 - The format check runs on the latest Go only
 - The changelog heading is the one spelling of a release; CI cuts the tag
diff --git a/docs/decisions.md b/docs/decisions.md
index 5729990..e4f8df1 100644
--- a/docs/decisions.md
+++ b/docs/decisions.md
@@ -121,6 +121,13 @@ this repo's own are.
 A script branches on the exit code and reads the named path or spelling, so those hold;
 wording improves in a minor.
 
+## A format holding a reference is fenced at link, and its errors name its path
+
+2026-09-24, larv-review. Goal 2: a format compiles once, and one holding a reference
+can compile only once bound, so its fences fire at link and name the category path as
+every link error does, a cell's with its line; one without a reference still names its
+file at compile. Valid while compilation needs the bound references.
+
 ## Raising the lowest supported Go is a major
 
 A consumer building on it breaks, which is the one test every rule above applies; Go's