S: <fee:cd avail="0">
    S:   <fee:objID>example.xyz</fee:objID>
    S:   <fee:command name="create">
    S:     <fee:period unit="y">2</fee:period>
    S:     <fee:reason>Only 1 year registration periods are
    S:     valid.</fee:reason>
    S:   </fee:command>
    S: </fee:cd>