diff --git a/doc/ChangeLog b/doc/ChangeLog
index 0d825b4a6..4954863b8 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,3 +1,7 @@
+2002-10-19  David Shaw  <dshaw@jabberwocky.com>
+
+	* gpg.sgml: Clarify --force-mdc, and document --disable-mdc.
+
 2002-10-17  Werner Koch  <wk@gnupg.org>
 
 	* faq.raw: New upstream version with new sections 1.3, 5.8, 6.20
diff --git a/doc/gpg.sgml b/doc/gpg.sgml
index fe8eefd0c..8cb5ccd7c 100644
--- a/doc/gpg.sgml
+++ b/doc/gpg.sgml
@@ -1788,13 +1788,21 @@ changes the default hash algorithm for v3 RSA keys from MD5 to SHA-1.
 Reset the --force-v4-certs option.
 </para></listitem></varlistentry>
 
-
 <varlistentry>
 <term>--force-mdc</term>
 <listitem><para>
-Force the use of encryption with appended manipulation code.  This is
-always used with the newer ciphers (those with a blocksize greater
-than 64 bit).
+Force the use of encryption with a modification detection code.  This
+is always used with the newer ciphers (those with a blocksize greater
+than 64 bits), or if the recipient key has one of those ciphers as a
+preference.
+</para></listitem></varlistentry>
+
+<varlistentry>
+<term>--disable-mdc</term>
+<listitem><para>
+Disable the use of the modification detection code.  Note that by
+using this option, the encrypted message becomes vulnerable to a
+message modification attack.
 </para></listitem></varlistentry>
 
 <varlistentry>