A method of determining compatibility between a reproducing medium and a recording/reproducing apparatus, comprising:
- installing said reproducing medium in said recording/reproducing apparatus;
- comparing a base part version of the recording/reproducing apparatus with a detailed extended part version stored in a reserved zone of a physical format information zone of said reproducing medium;
- and
- determining reproducing compatibility based upon said comparing said base part version with said detailed extended part version, wherein said detailed extended part version is recorded in the form of n.x.