((a)) ** In general** An appropriate official shall, shortly before release of the sex offender from custody, or, if the sex offender is not in custody, immediately after the sentencing of the sex offender, for the offense giving rise to the duty to register—
((1)) inform the sex offender of the duties of a sex offender under this subchapter and explain those duties;
((2)) require the sex offender to read and sign a form stating that the duty to register has been explained and that the sex offender understands the registration requirement; and
((3)) ensure that the sex offender is registered.
((b)) ** Notification of sex offenders who cannot comply with subsection (a)** The Attorney General shall prescribe rules for the notification of sex offenders who cannot be registered in accordance with subsection (a).