This excerpt taken from the BBEP 8-K filed Oct 16, 2006.
Section 4.1 Certificates.
Upon the Partnerships issuance of Common Units to any Person, the Partnership shall issue, upon the request of such Person, one or more Certificates in the name of such Person evidencing the number of such Units being so issued. In addition, upon the General Partners request, the Partnership shall issue to it one or more Certificates in the name of the General Partner evidencing its General Partner Interest and (b) upon the request of any Person owning any other Partnership Securities other than Common Units, the Partnership shall issue to such Person one or more certificates evidencing such other Partnership Securities other than Common Units. Certificates shall be executed on behalf of the Partnership by the President or any Executive Vice President, Senior Vice President or Vice President and the Chief Financial Officer or the Secretary or any Assistant Secretary of the General Partner. No Common Unit Certificate shall be valid for any purpose until it has been countersigned by the Transfer Agent; provided, however, that if the General Partner elects to issue Common Units in global form, the Common Unit Certificates shall be valid upon receipt of a certificate from the Transfer Agent certifying that the Common Units have been duly registered in accordance with the directions of the Partnership.