As used in this article, “terms of the trust” means the written trust instrument of an irrevocable trust or those provisions of a written trust instrument in effect at the settlor’s death that describe or affect that portion of a trust that has become irrevocable at the death of the settlor. In addition, “terms of the trust” includes, but is not limited to, signatures, amendments, disclaimers, and any directions or instructions to the trustee that affect the disposition of the trust. “Terms of the trust” does not include documents which were intended to affect disposition only while the trust was revocable. If a trust has been completely restated, “terms of the trust” does not include trust instruments or amendments which are superseded by the last restatement before the settlor’s death, but it does include amendments executed after the restatement. “Terms of the trust” also includes any document irrevocably exercising a power of appointment over the trust or over any portion of the trust which has become irrevocable.