Add a few meta-attribute descriptions; rewrite the meta-attribure list description to mean that it is expected that all used meta-attributes are described in the manual.

doc/meta.xml

@@ -84,8 +84,7 @@ hello-2.3  A program that produces a familiar, friendly greeting
 
 <section><title>Standard meta-attributes</title>
 
-<para>The following meta-attributes have a standard
-interpretation:</para>
+<para>It is expected that each meta-attribute is one of the following:</para>
 
 <variablelist>
 
@@ -112,12 +111,23 @@ interpretation:</para>
     package.</para></listitem>
   </varlistentry>
 
+  <varlistentry>
+    <term><varname>version</varname></term>
+    <listitem><para>Package version.</para></listitem>
+  </varlistentry>
+
   <varlistentry>
     <term><varname>homepage</varname></term>
     <listitem><para>The package’s homepage.  Example:
     <literal>http://www.gnu.org/software/hello/manual/</literal></para></listitem>
   </varlistentry>
 
+  <varlistentry>
+    <term><varname>downloadPage</varname></term>
+    <listitem><para>The page where a link to the current version can be found.  Example:
+    <literal>http://ftp.gnu.org/gnu/hello/</literal></para></listitem>
+  </varlistentry>
+
   <varlistentry>
     <term><varname>license</varname></term>
     <listitem><para>The license for the package. One from the
@@ -195,6 +205,16 @@ meta.hydraPlatforms = [];
     they are fixed.</para></listitem>
   </varlistentry>
 
+  <varlistentry>
+    <term><varname>updateWalker</varname></term>
+    <listitem><para>If set to <literal>true</literal>, the package is
+    tested to be updated correctly by the <literal>update-walker.sh</literal>
+    script without additional settings. Such packages have
+    <varname>meta.version</varname> set and their homepage (or
+    the page specified by <varname>meta.downloadPage</varname>) contains
+    a direct link to the package tarball.</para></listitem>
+  </varlistentry>
+
 </variablelist>
 
 
@@ -256,9 +276,9 @@ to indicate the specific license:
 </variablelist>
 
 </para>
-  
+
 
 </section>
-  
+
 
 </chapter>