README.md

@@ -709,7 +709,9 @@ tokens add cost in proportion to the output.
   category, which both reference. That settled, a record's column fences run at `New`
   too, so a category that loads renders as whichever shape is asked for, and a reference
   reaching back into a category through another one is refused there as the overlap it
-  is.
+  is. Which reads those fences weigh differs on purpose: a record-only template's inert
+  format renders nothing, so a `drawGroup` on it can never matter and is refused, while
+  one on a rendering format can matter to a caller that bare-references it.
 - **A record's column set is fixed before the first draw.** Only a category-level
   template is a record: a path descending into a field, or naming a folder or a
   choice, errors. A tail may pass through a choice whose variants carry different

draw.go

@@ -154,8 +154,7 @@ func (c *drawCheck) checkRecordDraws(path string, n node) error {
 	if !ok || !t.record {
 		return nil
 	}
-	// A record's columns are its fields, which its format need not render at all, so the
-	// reads to weigh are theirs rather than the template's own.
+	// A record-only template's format renders nothing, so weigh the columns, not the format.
 	columns := recordColumns(t)
 	reads := false
 	for _, name := range columns {

graph.go

@@ -197,9 +197,6 @@ func checkRenders(s nodeScope) error {
 		return err
 	}
 	fence := &drawCheck{}
-	// One pass refuses a draw group that splits nothing and notes whether the scope binds a
-	// reference at all: weighing what a render's draws hold walks every node it renders, and
-	// with nothing bound there is no draw to share, so the shipped set pays for neither walk.
 	refs := false
 	if err := s(func(path string, n node) error {
 		if t, ok := n.(*template); ok && len(t.refs) > 0 {

perf_test.go

@@ -51,11 +51,7 @@ func TestNoRenderAllocRegression(t *testing.T) {
 	}
 }
 
-// A record's fences read the compiled tree, so they belong to New, not to a draw.
-// A reference path read across a repeat, and one read in a named draw group. The repeat
-// prices both measures that keep a render's draw set off the heap — inlining expandAnew
-// into render's loop, or keying a draw group's map with the scope's own string, costs an
-// allocation an iteration — while the draw group holds the group path's own count.
+// The repeat shape prices both escape measures: dropping either costs an alloc an iteration.
 func TestNoReferenceAllocRegression(t *testing.T) {
 	word := `{"format":"{w}","w":["alpha","beta","gamma","delta"]}`
 	for _, s := range []struct {
@@ -78,6 +74,7 @@ func TestNoReferenceAllocRegression(t *testing.T) {
 	}
 }
 
+// A record's fences read the compiled tree, so they belong to New, not to a draw.
 func TestNoRecordAllocRegression(t *testing.T) {
 	for _, s := range []struct{ name, json string }{
 		{"record 3 columns", `{"format":"","a":"x","b":"y","c":"z"}`},