The national television circuits should be so adjusted that, when they are connected to the international television link, the amplitude of the video signals at the video interconnection points is in accordance with Recommendation N.60.
ITU-T N.61 SPANISH-1988 Referenced Document
ITU-T N.60 Nominal Amplitude of Video Signals at Video Interconnection Points - Maintenance of International Sound- Programme and Television Transmission Circuits (Study Group IV) 6 pp*, 1993-01-01 Update
ITU-T N.61 SPANISH-1988 history
1988ITU-T N.61 SPANISH-1988 Measurements to Be Made Before the Line-up Period That Precedes a Television Transmission