PREFACE This Publication reproduces the formal Reports and Study Questions of the C.I.S.P.R. on matters relating to radio interference and its suppression. The Publication is divided into two parts@ as follows: Part 1: Reports; Part 2: Study Questions. The promulgation of formal C.I.S.P.R. Reports and Study Questions commenced at the C.I.S.P.R. meeting in Brussels in 1956. The Reports and Study Questions in this Publication therefore carry the date of either that meeting or a subsequent one@ but in every case the Reports and Study Questions were confirmed or approved at the meeting in Stockholm in 1964.