What is the XML rule for Name-Based Object Naming - Variable Length?

<rule>    <description>Name-Based Object Naming - Variable Length</description>    <conditions>        <and>            <if-class-name op="equal">User</if-class-name>          </and>      </conditions>    <actions>        <do-set-local-variable name="tmpSurname">            <arg-string>                <token-op-attr name="urn:ietf:params:scim:schemas:core:2.0:User:name.familyName"/>              </arg-string>          </do-set-local-variable>        <do-set-local-variable name="stripSurname">            <arg-string>                <token-xpath expression="translate($tmpSurname,&quot;-+'&quot;,&quot;&quot;)"/>              </arg-string>          </do-set-local-variable>        <do-set-local-variable name="tmpGivenname">            <arg-string>                <token-op-attr name="urn:ietf:params:scim:schemas:core:2.0:User:name.givenName"/>              </arg-string>          </do-set-local-variable>        <do-set-local-variable name="stripGivenname">            <arg-string>                <token-xpath expression="translate($tmpGivenname,&quot;-+'&quot;,&quot;&quot;)"/>              </arg-string>          </do-set-local-variable>        <do-set-local-variable name="unique-cn" scope="driver">            <arg-string>                <token-unique-name counter-digits="3" counter-pad="false" counter-pattern="first" name="urn:ietf:params:scim:schemas:core:2.0:User:userName" scope="subtree">                    <arg-string>                        <token-lower-case>                            <token-substring length="1">                                <token-local-variable name="stripGivenname"/>                              </token-substring>                            <token-local-variable name="stripSurname"/>                          </token-lower-case>                      </arg-string>                    <arg-string>                        <token-lower-case>                            <token-substring length="2">                                <token-local-variable name="stripGivenname"/>                              </token-substring>                            <token-local-variable name="stripSurname"/>                          </token-lower-case>                      </arg-string>                    <arg-string>                        <token-lower-case>                            <token-substring length="3">                                <token-local-variable name="stripGivenname"/>                              </token-substring>                            <token-local-variable name="stripSurname"/>                          </token-lower-case>                      </arg-string>                  </token-unique-name>              </arg-string>          </do-set-local-variable>      </actions>  </rule>