Line of Authority
"The First Presidency has authorized the gathering of information to record Melchizedek priesthood lines of authority," said Stephen Carlile, in the Member and Statistical Records Division of the Church's Finance and Records Department. "It began under President Gordon B. Hinckley, who felt that the Church should start gathering information needed to record Melchizedek Priesthood lines of authority." The Church can now provide priesthood line of authority information as a service to members upon request. [..]
If you wish to request your priesthood line of authority, include your full legal name, birth date, membership record number (available on a temple recommend or from your ward clerk), the name of the individual who ordained you to the office of elder or high priest (if known), and your return address and telephone number or e-mail address. More: Source 1