<?xml version="1.0"?>
<interfaceDefinition>
  <node name="login" owner="login">
    <children>
      <tagNode name="user">
        <properties>
          <help>User name</help>
          <constraint>
            <regex>[a-z][a-zA-Z0-9]+</regex>
          </constraint>
          <constraintErrorMessage>User name must start with a letter and consist of letters and digits</constraintErrorMessage>
        </properties>
        <children>
          <leafNode name="full-name">
            <properties>
              <help>User full name</help>
            </properties>
          </leafNode>
        </children>
      </tagNode>
    </children>
  </node>
</interfaceDefinition>