diff --git a/xtmfile/header.rb b/xtmfile/header.rb
index 35b1825..7e7c2a8 100644
--- a/xtmfile/header.rb
+++ b/xtmfile/header.rb
@@ -3,6 +3,7 @@ require 'rubygems'
 gem 'bindata', '~> 1.2.1'
 require 'bindata'
 
+# FIXME: set default values for header fields
 module XtmFile
 
 	#