A few scribbles toward the DTD.
diff --git a/Doc/sgml/python.dtd b/Doc/sgml/python.dtd
new file mode 100644
index 0000000..e9bf50a
--- /dev/null
+++ b/Doc/sgml/python.dtd
@@ -0,0 +1,43 @@
+<!ENTITY % common.att "
+ id ID #IMPLIED
+ role NMTOKEN #IMPLIED">
+
+<!-- include the OASIS Exchange Table Model -->
+<!ENTITY oasis-tables.mod
+ PUBLIC "-//OASIS//DTD Exchange Table Model 19960430//EN">
+&oasis-tables.mod;
+
+<!ELEMENT input - - EMPTY>
+<!ATTLIST input
+ %common.att;
+ xml:link #FIXED "simple"
+ show CDATA "embed"
+ embed CDATA "auto"
+ source CDATA #REQUIRED>
+
+<!ELEMENT (function|constant) - - (#PCDATA)>
+<!ATTLIST (function|constant)
+ %common.att;
+ index (index|noindex) noindex
+ module CDATA #IMPLIED>
+
+<!ELEMENT method - - (#PCDATA)>
+<!ATTLIST method
+ %common.att;
+ index (index|noindex) noindex
+ module CDATA #IMPLIED
+ class CDATA #IMPLIED>
+
+<!ELEMENT module - - (#PCDATA)>
+<!ATTLIST module
+ %common.att;
+ link (link|nolink) nolink
+ package CDATA #IMPLIED>
+
+<!ELEMENT signature - - (name, super*, args?)>
+<!ELEMENT name - - (#PCDATA)>
+<!ELEMENT super - - (#PCDATA)>
+<!ELEMENT args - - (#PCDATA)>
+
+<!ELEMENT %descriptor.class; - - (sig+, description)>
+<!ELEMENT description - - (%para.mix;)>