The resource-refType contains a declaration of a
Deployment Component's reference to an external resource. It
consists of an optional description, the resource manager
connection factory reference name, the indication of the
resource manager connection factory type expected by the
Deployment Component code, the type of authentication
(Application or Container), and an optional specification of
the shareability of connections obtained from the resource
(Shareable or Unshareable).

Example:

<resource-ref>
    <res-ref-name>jdbc/EmployeeAppDB</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
    <res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>