This is a built-in template used for replacing text in JSP, e.g.
  <html><body>
    Hello!
  </body></html>

with internationalized JSP custom tag usage, e.g.
  <html><body>
    <bean:message key="HelloKey"/>
  </body></html>

The template is editable. Along with expressions allowed in a JSP context, you can also use predefined variables that will be then expanded into the corresponding values.
Predefined variables will take the following values:
${PROPERTY_KEY}   Property key name which is specified in the corresponding properties file.
${PROPERTY_VALUE}   Property value which is specified in the corresponding properties file. This is an original JSP text selection value.