diff --git a/node.go b/node.go
index 76ddbbd..a0c4791 100644
--- a/node.go
+++ b/node.go
@@ -257,11 +257,9 @@ func weightOf(raw any) (float64, error) {
 // separates the segments of a path, '|' the arms of a token, '(' opens a function
 // call and '}' ends the token. A name carrying one is reachable by no format, so it
 // is rejected where it is authored rather than at the token that cannot reach it.
-// ')' is absent deliberately — it is spellable on its own, so it stays legal.
 const reservedInName = ".|(}"
 
-// reservedList is reservedInName spelled out for an error message, so the two
-// cannot drift apart.
+// reservedList spells reservedInName for an error message, so the two cannot drift.
 var reservedList = strings.Join(strings.Split(reservedInName, ""), " ")
 
 // checkName rejects a name the dot path and {token} grammars cannot spell. Both a
diff --git a/render.go b/render.go
index 865d0ae..d8e6c91 100644
--- a/render.go
+++ b/render.go
@@ -138,8 +138,8 @@ func expand(s *session, t *template) string {
 	var b strings.Builder
 	b.Grow(t.grow)
 	// One draw per held name, for this expansion only: a nested template and each
-	// repeat iteration get their own, since each is its own expansion. held stays a
-	// local: nothing hands it to a builtin, so it and its maps never leave the stack.
+	// repeat iteration get their own, since each is its own expansion. held reaches
+	// no further than readField, which keeps it and its maps on the stack.
 	var held *draws
 	if len(t.held) > 0 {
 		held = &draws{
@@ -157,8 +157,7 @@ func expand(s *session, t *template) string {
 		case 'f':
 			b.WriteString(readField(s, t, held, o.arms[s.IntN(len(o.arms))]))
 		case 'b':
-			// A calc's operands are read here, in the order its expression first
-			// names them, so the value it computes is the value the format showed.
+			// Read in the order calcVars fixed, which is what op.operands holds.
 			var operands []string
 			if len(o.operands) > 0 {
 				operands = make([]string, len(o.operands))
diff --git a/template.go b/template.go
index 3c4b9a1..cf1f764 100644
--- a/template.go
+++ b/template.go
@@ -317,9 +317,8 @@ type op struct {
 	r    rune   // kind 'c'
 	arms []arm  // kind 'f': the '|' alternatives, split into key and path once
 	call callFn
-	// operands names the sibling fields a {calc()} reads, in the order its
-	// expression first names them. expand reads them before the call, so the
-	// evaluator never touches the node tree. nil for every other builtin.
+	// operands names the sibling fields a {calc()} reads, in the order calcVars
+	// fixed; expand reads them before the call. nil for every other builtin.
 	operands []string
 }