For purposes of this section, a disinterested person is one who has no beneficial interest in the trust that would be materially increased or decreased as a result of the creation, modification or revocation of the trust and a notary public or similar official may serve as a witness in cases where such official is a disinterested or credible person without regard to whether such notary public or similar official signs the writing as a witness or solely in a notarial capacity. Unless otherwise expressly prohibited by the terms of a writing described in this subsection, then-subject to the foregoing requirements regarding witnesses-such writing may be executed in counterparts.
Notwithstanding the foregoing, in the case of a writing that includes both provisions for dispositions that are consistent with the terms of the trust or any other writing permitted by this section and provisions for dispositions that are inconsistent with the terms of the trust or any other writing permitted by this section, such writing shall be admissible under this section as evidence of the intended disposition of those items of tangible personal property that would be disposed of by the provisions of the writing that are not inconsistent with the terms of the trust or any other writing permitted by this section. The writing may be referred to as one in existence at the time of the trustor's death; it may be prepared before or after the execution of the trust instrument; it may be altered by the trustor after its preparation; and it may be a writing which has no significance apart from its effect upon the dispositions made by the trust instrument. This subsection (d) shall apply only with respect to dispositions intended to take effect upon the death of the trustor, although such a writing may direct that an item or items of tangible personal property shall be administered as part of a trust or trusts created under the trust pursuant to terms of the trust instrument that were executed pursuant to the provisions of subsections (a) and (b) of this section.
12 Del. C. § 3545