A Custody and Control Form, often called a CCF, is what documents the chain of custody of a specimen. In its paper form, it is a five-part form. Page one is the Lab Copy. Page 2 is for the MRO. Page 3 is the Employer Copy. Page 4 is for the Collector and the last page is the Donor Copy.
Many CCFs are electronic (eCCF), though a paper copy still accompanies the specimen to the lab.