diff --git a/TODO b/TODO
index 183ea6ca45a355317fda30dd4b62b15217ae2be4..a4f3b1716473f71182e9436a229bc0470d4b7ead 100644
--- a/TODO
+++ b/TODO
@@ -16,9 +16,6 @@ General
 * Add xdg-autostart
 
 xdg-su:
-* The summary is incorrect, it suggests that it can only run things as
-root which is incorrect according to the main body of the document.
-* The -c option is listed in the synopsis, but not in options.
 * It would be useful if it was possible to distinguish between a failure
 because of a bad password or some other failure.
 * use sudo style syntax, drop -c option
diff --git a/scripts/desc/xdg-su.xml b/scripts/desc/xdg-su.xml
index 53a0f321c0b3011316c725b5fa8b315bc37be01f..b4e1b7ec9e037fca18b53c70af84aa7d8106382e 100644
--- a/scripts/desc/xdg-su.xml
+++ b/scripts/desc/xdg-su.xml
@@ -30,7 +30,7 @@
 
   <refnamediv>
     <refname>xdg-su</refname>
-    <refpurpose>run a GUI program as root after prompting for the root password</refpurpose>
+    <refpurpose>run a GUI program as another user (typically root) after prompting for that user's password</refpurpose>
   </refnamediv>
 
   <refsynopsisdiv>
@@ -67,6 +67,15 @@
   <refsect1 id="options">
     <title>Options</title>
     <variablelist>
+      <varlistentry>
+	<term><option>-c <replaceable>command</replaceable></option></term>
+	<listitem>
+	  <simpara>
+	    the command to run. This argument is mandatory.
+	  </simpara>
+	</listitem>
+      </varlistentry>
+
       <varlistentry>
 	<term><option>-u <replaceable>user</replaceable></option></term>
 	<listitem>