WebDAVAuthenticMetadata

First, for each XML file within the "repo" folder create an acompaning file with a ".meta" extension like the "step4" example is doing:

<?xml version="1.0" encoding="UTF-8"?>
<metapage>
  <author>me</author>
  <category>catb</category>
  <state>edited</state>
</metapage>

Add 2 additional match nodes to your pipeline:

<map:match pattern="page/**">
  <map:aggregate element="aggregation" label="content">
    <map:part src="cocoon:/raw/{1}"/>
    <map:part src="cocoon:/meta/{1}"/>
  </map:aggregate>
  <map:serialize type="xml"/>
</map:match>
<map:match pattern="meta/**">
  <map:generate src="{global:staging}repo/{1}.meta"/>
  <map:serialize type="xml"/>
</map:match>

Now create 2 additional files within the "authentic" folder, aggregation.xsd (the XML schema)

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
<xs:element name="aggregation">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="page" minOccurs="1" maxOccurs="1"/>
      <xs:element ref="metapage" minOccurs="1" maxOccurs="1"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="page">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="title"/>
      <xs:element ref="content"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="content">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="para" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="title" type="xs:string"/>
<xs:element name="para">
  <xs:complexType mixed="true">
    <xs:sequence minOccurs="0" maxOccurs="unbounded">
      <xs:element ref="emphasis" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="image" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="link" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="emphasis">
  <xs:complexType mixed="true"/>
</xs:element>
<xs:element name="image">
  <xs:complexType>
    <xs:attribute name="href" type="xs:string" use="required"/>
    <xs:attribute name="height" type="xs:long"/>
    <xs:attribute name="width" type="xs:long"/>
  </xs:complexType>
</xs:element>
<xs:element name="link">
  <xs:complexType mixed="true">
    <xs:attribute name="href" type="xs:string" use="required"/>
  </xs:complexType>
</xs:element>
<xs:element name="metapage">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="author" minOccurs="1" maxOccurs="1"/>
      <xs:element ref="category" minOccurs="1" maxOccurs="1"/>
      <xs:element ref="state" minOccurs="1" maxOccurs="1"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="author" type="xs:string"/>
<xs:element name="category" type="xs:string"/>
<xs:element name="state" type="xs:string"/>
</xs:schema>

and aggregation.sps (the authetic-specific stylesheet)

<?xml version="1.0" encoding="UTF-8"?>
<structure version="2" schemafile="aggregation.xsd" workingxmlfile="" templatexmlfile="">
<nspair prefix="xs" uri="http://www.w3.org/2001/XMLSchema"/>
<template>
  <match overwrittenxslmatch="/"/>
  <children>
    <template>
      <match match="aggregation"/>
      <children>
        <template>
          <match match="metapage"/>
          <children>
            <xpath allchildren="1"/>
          </children>
        </template>
        <newline/>
        <newline/>
        <template>
          <match match="page"/>
          <children>
            <template>
              <match match="title"/>
              <children>
                <xpath allchildren="1">
                  <styles color="#0000A0" font-size="larger" font-weight="bold" text-decoration="underline"/>
                </xpath>
              </children>
            </template>
            <template>
              <match match="content"/>
              <children>
                <template>
                  <match match="para"/>
                  <children>
                    <paragraph paragraphtag="p">
                      <children>
                        <xpath allchildren="1"/>
                      </children>
                    </paragraph>
                  </children>
                </template>
              </children>
            </template>
          </children>
        </template>
      </children>
    </template>
  </children>
</template>
<template>
  <match match="author"/>
  <children>
    <text fixtext="Author: "/>
    <field ownvalue="1">
      <properties size="19" value=""/>
    </field>
    <newline/>
    <newline/>
  </children>
</template>
<template>
  <match match="category"/>
  <children>
    <text fixtext="Category: "/>
    <select ownvalue="1">
      <properties size="0"/>
      <selectoption description="Cat A" value="cata"/>
      <selectoption description="Cat B" value="catb"/>
      <selectoption description="Cat C" value="catc"/>
    </select>
    <newline/>
    <newline/>
  </children>
</template>
<template>
  <match match="emphasis"/>
  <children>
    <xpath allchildren="1">
      <styles font-weight="bold"/>
    </xpath>
  </children>
</template>
<template>
  <match match="image"/>
  <children>
    <image>
      <properties border="0"/>
        <imagesource>
          <xpath value="@href"/>
        </imagesource>
      </image>
  </children>
</template>
<template>
  <match match="link"/>
  <children>
    <link>
      <hyperlink>
        <xpath value="@href"/>
      </hyperlink>
      <children>
        <xpath allchildren="1"/>
      </children>
    </link>
  </children>
</template>
<template>
  <match match="metapage"/>
  <children>
    <newline/>
    <template>
      <match match="author"/>
      <children>
        <xpath allchildren="1"/>
      </children>
    </template>
    <newline/>
    <template>
      <match match="category"/>
      <children>
        <xpath allchildren="1"/>
      </children>
    </template>
    <newline/>
    <template>
      <match match="state"/>
      <children>
        <xpath allchildren="1"/>
      </children>
    </template>
    <newline/>
  </children>
</template>
<template>
  <match match="page"/>
  <children>
    <xpath allchildren="1"/>
  </children>
</template>
<template>
  <match match="state"/>
  <children>
    <text fixtext="State: "/>
    <select ownvalue="1">
      <properties size="0"/>
      <selectoption description="New" value="new"/>
      <selectoption description="Edited" value="edited"/>
      <selectoption description="Reviewed" value="reviewed"/>
      <selectoption description="Released" value="released"/>
    </select>
    <newline/>
    <newline/>
  </children>
</template>
</structure>

Now change your "file2html.xsl" stylesheet to reference these files instead of "content.xsd" and "content.sps".

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:param name="file"></xsl:param>
<xsl:param name="sitemapURI"></xsl:param>
<xsl:param name="requestURI"></xsl:param>
<xsl:param name="serverName"></xsl:param>
<xsl:param name="serverPort"></xsl:param>

<xsl:template match="/page">
  <html>
    <body>
      <OBJECT id="objPlugIn"  
              Classid="clsid:46987108-BA64-4fd1-A947-1BF7DA938FC0" width="700" height="500"> 
        <xsl:attribute name="CodeBase">http://<xsl:value-of select="$serverName"/>:<xsl:value-of select="$serverPort"/><xsl:value-of select="substring-before($requestURI, $sitemapURI)"/>authentic/AuthenticBrowserEdition.cab</xsl:attribute>
        <PARAM NAME="LicKey" VALUE="<YOUR LICENSE KEY>"/> 
        <PARAM NAME="LicServer">
          <xsl:attribute name="VALUE">http://<xsl:value-of select="$serverName"/></xsl:attribute>
        </PARAM>
        <PARAM NAME="XMLDataURL">
          <xsl:attribute name="VALUE">http://<xsl:value-of select="$serverName"/>:<xsl:value-of select="$serverPort"/><xsl:value-of select="substring-before($requestURI, $sitemapURI)"/>raw/<xsl:value-of select="$file"/></xsl:attribute>
        </PARAM>
        <PARAM NAME="XMLDataSaveURL">
          <xsl:attribute name="VALUE">http://<xsl:value-of select="$serverName"/>:<xsl:value-of select="$serverPort"/><xsl:value-of select="substring-before($requestURI, $sitemapURI)"/>write/<xsl:value-of select="$file"/></xsl:attribute>
        </PARAM>
        <PARAM NAME="SPSDataURL">
          <xsl:attribute name="VALUE">http://<xsl:value-of select="$serverName"/>:<xsl:value-of select="$serverPort"/><xsl:value-of select="substring-before($requestURI, $sitemapURI)"/>authentic/aggregation.sps</xsl:attribute>
        </PARAM>
        <PARAM NAME="SchemaDataURL">
          <xsl:attribute name="VALUE">http://<xsl:value-of select="$serverName"/>:<xsl:value-of select="$serverPort"/><xsl:value-of select="substring-before($requestURI, $sitemapURI)"/>authentic/aggregation.xsd</xsl:attribute>
        </PARAM>
        <PARAM NAME="EntryHelpersEnabled" VALUE="TRUE"/>
        <PARAM NAME="EntryHelperWindows" VALUE="3"/>
      </OBJECT> 
      <br/>
      <input type="button" name="submit1" value="Save" onClick="objPlugIn.SavePOST()"/>
    </body>
  </html>
</xsl:template>

</xsl:stylesheet>

Now you already can edit your meta data together with your XML document. Adjust your "stream2write.xsl" stylesheet to separate the data and metadata down the pipeline again:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns:req="http://apache.org/cocoon/request/2.0"
                xmlns:source="http://apache.org/cocoon/source/1.0">

<xsl:param name="file"></xsl:param>

<xsl:template match="/aggregation">
<page>
  <xsl:apply-templates/>
</page>
</xsl:template>

<xsl:template match="page">
  <source:write create="true">
    <source:source><xsl:value-of select="$file"/></source:source>
    <source:fragment>
      <xsl:copy-of select="."/>
    </source:fragment>
  </source:write>
</xsl:template>

<xsl:template match="metapage">
  <source:write create="true">
    <source:source><xsl:value-of select="$file"/>.meta</source:source>
    <source:fragment>
      <xsl:copy-of select="."/>
    </source:fragment>
  </source:write>
</xsl:template>

</xsl:stylesheet>

Adjust your sitemap to exclude your ".meta" files from folder traversal like the "step4" sample is doing.