Finally add comment to help future maintainers with debugging 3-pass …

…RELAX NG pattern reduction code (which I wrote > 2 weeks ago).

odds/odd2relax.xsl

@@ -225,21 +225,18 @@ of this software, even if advised of the possibility of such damage.
         <xsl:apply-templates mode="pass3"/>
       </xsl:for-each>
     </xsl:variable>
+    <!-- The variable $pass3 is not really needed, but is left here to
+         make it easier to write debugging code. Remember, though,
+         that if you want to see what the intermediate stages look
+         like you cannot use <result-document>, because this template
+         is called from within a variable defintion. You can get
+         around this by outputing each intermediate stage ($pass1 &
+         $pass2) into the output file in addition to the final stage
+         ($pass3). This makes for great debugging, but also for a
+         useless output RELAX NG schema, of course.  You can see a
+         version of this in commit 522e84e from 2023-10-06.
+            — Syd, 2023-10-09 -->
     <xsl:sequence select="$pass3"/>
-    <!--
-      <!-\- debugging output: -\->
-    <a:documentation> ========= above is pass3, next is pass2 ========= </a:documentation>
-    <rng:div xml:id="pass2">
-      <xsl:copy-of select="$pass2"/>
-    </rng:div>
-    <a:documentation> ========= above is pass2, next is pass1 ========= </a:documentation>
-    <rng:div xml:id="pass1">
-      <xsl:copy-of select="$pass1"/>
-    </rng:div>
-    <a:documentation> ========= above is pass1, next is input ========= </a:documentation>
-    <rng:div xml:id="pass0">
-      <xsl:copy-of select="/*"/>
-    </rng:div> -->
   </xsl:template>
 
   <xsl:template match="tei:moduleSpec">