diff --git a/imxml2epub.py b/imxml2epub.py
index 630cab1..fb3b6f6 100755
--- a/imxml2epub.py
+++ b/imxml2epub.py
@@ -1,6 +1,13 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8; mode: python -*-
-# Time-stamp: <2018-06-01 16:17:44 (kthoden)>
+# Time-stamp: <2018-08-22 15:49:01 (kthoden)>
+
+""" Convert a customized DocBook XML file into a set of files that
+constitute the contents of an EPUB file.
+
+Input file is a customized DocBook XML that has been generated either
+with eoatex2imxml or tei2imxml.
+"""
 
 import os
 import sys