A method for referencing and interconnecting contents, applications and metadata to an audiovisual content is described, especially for iTV of for distribution on DVD, which comprises the step of inserting a digital watermark into the audiovisual content during an audiovisual content encoding step, the digital watermark being possibly used for allowing a user to reproduce or exploit additional contents supplementing those provided by the audiovisual content, wherein the digital watermark is inserted into the audiovisual content as data frame with header and body by subdividing it into a plurality of consecutive ‘I’ frames and forcing the parity of LSBs of mid-frequency providing an auxiliary watermark channel, e.g. in an MPEG2 transport stream.