Optical disc and physical address format

An optical disc medium compares a track groove, along which main information is recorded. The track groove is divided into a plurality of blocks. The plurality of blocks each includes a plurality of frames. The plurality of frames each includes one shape of wobbles indicating sub information, among a plurality of prescribed shapes of wobbles. The plurality of blocks each has address information. The address information is represented by a string of at least one piece of sub information represented by the shape of wobbles of at least one of the plurality of frames.