--- a/plugins/sourcetags.py
+++ b/plugins/sourcetags.py
@@ -1,3 +1,10 @@
+
+'''
+This software is licensed under the GPL (GNU General Public License) version 2
+as it appears here: http://www.gnu.org/copyleft/gpl.html
+It is also included with this archive as `gpl.txt <gpl.txt>`_.
+'''
+
 
 import wx
 import todo