This excerpt taken from the T 10-K filed Feb 26, 2007.
General Rule. During the lifetime of a Participant to whom an Award is granted, only the Participant (or such Participants legal representative) may exercise or receive payment of an Award. No Award (other than unrestricted Stock Payments upon receipt) may be sold, assigned, transferred (except as provided in the sentence above), exchanged, or otherwise encumbered or made subject to any creditors process, whether voluntary, involuntary or by operation of law, and any attempt to do so shall be of no effect. This Section 10.4(a) shall apply to all Awards except as provided in Sections 10.4(b) and 10.4(c) below.