phpmd.xml

<ruleset name="name-of-your-coding-standard"
  xmlns="http://pmd.sf.net/ruleset/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://pmd.sf.net/ruleset/1.0.0
                      http://pmd.sf.net/ruleset_xml_schema.xsd"
  xsi:noNamespaceSchemaLocation="http://pmd.sf.net/ruleset_xml_schema.xsd">
  <description>Description of your coding standard</description>

  <rule ref="rulesets/codesize.xml/CyclomaticComplexity" />
  <!-- ... -->
</ruleset>