diff --git a/refpolicy/doc/policy.dtd b/refpolicy/doc/policy.dtd
index a9c3e11..2e063a8 100644
--- a/refpolicy/doc/policy.dtd
+++ b/refpolicy/doc/policy.dtd
@@ -1,7 +1,7 @@
 <!ENTITY  % inline.class  "pre|p|ul|li">
 
 <!ELEMENT policy (module+,tunable*)>
-<!ELEMENT module (summary,description,interface+)>
+<!ELEMENT module (summary,description?,interface+)>
 <!ATTLIST module 
       name CDATA #REQUIRED
       layer CDATA #REQUIRED>
@@ -10,7 +10,7 @@
       name CDATA #REQUIRED
       dftval CDATA #REQUIRED>
 <!ELEMENT summary (#PCDATA)>
-<!ELEMENT interface (summary,description,securitydesc*,parameter+,infoflow)>
+<!ELEMENT interface (summary?,description,securitydesc?,parameter+,infoflow?)>
 <!ATTLIST interface name CDATA #REQUIRED>
 <!ELEMENT description (#PCDATA)>
 <!ELEMENT securitydesc (#PCDATA)>