This document replaces AV/C Digital Interface Command Set General Specification 4.0 [R17]. Reference [R17]covers the AV/C general command and response model, unit/subunit model, and standard unit and subunit commands including connection commands. The predecessor documents, AV/C Digital Interface Command Set General Specification Version 3.0 [R8], have been separated into two documents - the AV/C Digital Interface Command Set General Specification Version 4.0 and the AV/C Descriptor Mechanism Specification Version 1.0 documents [R10]. The document, - Enhancement to the AV/C General Specification Version3.0, Version 1.1 [R9] has been contained in reference [R10] while AV/C Info Block Types Specification Version 1.0 [R11] has been separated from reference [R9]. We encourage you strongly to read this document in conjunction with the references given below, as well as with any AV/C-related documents that may be created in the future.