diff --git a/stream/mts/encoder.go b/stream/mts/encoder.go
index 29aa83fc..e6d10a61 100644
--- a/stream/mts/encoder.go
+++ b/stream/mts/encoder.go
@@ -89,6 +89,8 @@ const (
 )
 
 // TODO: make this not global.
+// Meta allows addition of metadata to encoded mts from outside of this pkg.
+// See meta pkg for usage.
 var Meta *meta.Data
 
 var (