This excerpt taken from the CVS 8-K filed Aug 15, 2006.
. Trustee to Sign Amendments, Etc. The Trustee shall sign any amended or supplemental Indenture authorized pursuant to this Article 9 if the amendment or supplement does not adversely affect the rights, duties, liabilities or immunities of the Trustee. If it does, the Trustee may but need not sign it. In signing such amendment or supplement the Trustee shall be provided with, and (subject to Section 7.01) shall be fully protected in relying upon, an Officers Certificate and an Opinion of Counsel stating that such amendment or supplement is authorized or permitted pursuant to this Indenture. The Company shall not sign any amendment or supplemental Indenture until the Board of Directors approves any such amendment or supplemental Indenture.