diff --git a/notes.txt b/notes.txt
index 7836bb0..696094d 100644
--- a/notes.txt
+++ b/notes.txt
@@ -30,6 +30,7 @@ formatter
 pretty
 notes in formatting
 format: test back and forth equivalence of char classes
+format: test comments, first apply comments in the syntax
 
 [problems]
 can the root be an alias? check the commit mechanism
diff --git a/syntax.go b/syntax.go
index d51c8ec..d98ee9a 100644
--- a/syntax.go
+++ b/syntax.go
@@ -24,6 +24,7 @@ type formatFlags int
 const (
 	formatNone   formatFlags = 0
 	formatPretty formatFlags = 1 << iota
+	formatIncludeComments
 )
 
 // if min=0&&max=0, it means min=1,max=1