(a) Denial of a 4-D claim by a board must be accompanied by a statement specifying the reason(s) for such denial as prescribed in §§ 1633.9, 1651.4 and 1653.3 of this chapter. The reason(s) must in turn, be supported by evidence in the registrant's file.

(b) If the board's denial is based on statements by the registrant or his witnesses at a personal appearance or on documentation in the registrant's file, such basis will be fully explained in the statement of reasons accompanying the denial.