513. Persons subject to custodial sentences.

When a custodial sentence has been passed on any person in respect of a service offence1, or an order detaining a person for the commission of an offence during the currency of a detention and training order2 has been made, that person may be detained in service custody until he is committed to the appropriate establishment3. If a person is outside England and Wales when a custodial sentence is passed on him in respect of a service offence, or such an order is made in respect of him, he must as soon as practicable be removed to England and