A protocol and related techniques and platforms allow vendors to selectably extend the Media Transport Protocol (MTP), or other defined protocols to implement vendor-specific commands, data fields, instructions and other extension sets. According to embodiments of the invention in one regard, one or more extension space may be utilized to derive independent extension sets, in part by separating the extension space according to a unique identifier assigned to or associated with a given vendor. In embodiments that unique identifier may be or include an Internet DNS (Domain Name System) domain name, or other extension set name or identifier. According to the invention in one regard, because a DNS domain name may be independently registered and secured by participating vendors or manufacturers and by definition uniquely assigned, the separation of vendor extension sets by that type of name may be automatic and free from conflict. Vendors or manufacturers, such as makers of digital cameras, digital video cameras, audio players such as MP3 or other players, software vendors or others may therefore freely design extensions to the Media Transport Protocol or other protocols, without a need to clear those extensions with a standards body and with confidence that their commands, data fields and other extensions may be free from overlap with that of other manufacturers.