The present inventors have recognized that it is desirable to have the ability to modify video signals so they carry additional information (data) which can be received and used by a receiving device (e.g., a TV set or display device but which, for security reasons, is not recordable by standard video recorders. It is believed that this problem of video data conveyance without recordability has not been earlier recognized. For instance, the VBI (vertical blanking interval) of video signals is often used to carry (non-video) data such as closed captioning, but a standard VHS type VCR does record the VBI and also this data. However, current digital video recorders do not record the VBI, and it is believed that future digital recorders may record only, for instance, part of the amplitude of the VBI.