7.24. Power Management States

The power_management_states element lists the available states for power management.
<capabilities>
    <version major="3" minor="3">
        ...
        <power_management_states>
            <power_management_state>on</power_management_state>
            <power_management_state>off</power_management_state>
            <power_management_state>unknown</power_management_state>
        </power_management_states>
        ...
    </version>
</capabilities>