Certification of transfer
A shareholder transferring part of his holding hands his share certificate plus a transfer form to the comapny. Before the transfer form is handed to the purchaser the company marks on it that a certificate for x shares has been lodged at the company’s office. This is signed by the secretary and is said to be certification of transfer. It is accepted by the Stock Exchange as a good delivery of shares. The company then proceeds to make out two new certificates.
Reference: The Penguin Business Dictionary, 3rd edt.