1 files changed, 4 insertions, 0 deletions
diff --git a/const.go b/const.go
index f60090c..1b5d36e 100644
--- a/const.go
+++ b/const.go
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2022 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 package asciidoctor
 
 // List of passthrough substitutions.