anchor.diff:  [options="header", cols="1,3,1"]
   |=================
   | Element | Description | Required
  +|doctype|The document type of the emitted documents. |No; at most one can be specified
   |transform|A _Transform_ sink. .4+| No; at least one sink required
   |all|An _All_ sink.
   |snip|A _Snip_ sink.
   |output|An _Output_ sink.
   |=================
   
  +[[actors.all.children.doctype]]
  +===== Doctype element's attributes
  +
  +[options="header", cols="1,3,1"]
  +|=================
  +| Attribute | Description | Required
  +|publicID|The public identifier of the document type. | No unless _systemID_ is specified
  +|systemID|The system identifier of the document type. | No unless _publicID_ is specified
  +|=================
  +
   
   [[actors.snip]]
   === Snip filter
  
positive.code:     <all root="flora">
        <transform style="flora/styles/to-genera.xsl">
          <snip select="/genera/genus">
            <output destdir="flora/genera" refer="/genus/@name">
              <globmapper from="*" to="*.xml"/>
            </output>
  
negative.code:  . first reads and parses all files with '.xml' extension in 'flora' directory,
   . then collects all parsed documents into a new document whose document element is +<flora>...</flora>+,
   . then transforms this document with XSLT stylesheet 'flora/styles/to-genera.xsl',
   . then finds all fragments from the resulted document which matches XPath criterion +/genera/genus+ and inserts document type declarations like +<!DOCTYPE genus SYSTEM "genus.dtd">+ into them,
   . finally writes each fragment to a file whose path is 'flora-genera/XXX.xml', where +XXX+ is the string value of XPath expression +/genus/@name+ of each fragment document (that is, +XXX+ of the document element +<genus name="XXX">...</genus>+).
  
  Additionally, it might be noteworthy that:
  