dotPH offers the following service types:

RESERVE - With this option, the domain is parked on dotPH nameservers for free. This option also comes with free webforwarding.
ACTIVATE - Register domain with the service type set to ACTIVATE to be able to specify the nameservers that will be used by the domain.

In the example below the nameservers specified will be ignored, and the domain will be parked on dotph nameservers.

?
<Domain name="mydomain.com.ph">
<PaymentInfo>
?
<JD type="RegisterDomain" duration="2" ServiceType="RESERVE">
<Organization>Domains Inc</Organization>
?
<NameServers>
<NS1 name="ns1.others.ph" ip="203.167.64.32"/>
<NS2 name="ns2.others.ph" ip="203.167.64.35"/>
<NS3 name="" ip=""/>
</NameServers>