Define the registration support

Define the application registration opaque data field format for this service type. All applications that implement this service type must define the opaque data field in the application registration files, and they must all use the same opaque data field format in the application registration file entry.

Opaque data field formats for different services can vary, but they must be common for all implementations of a single service.

The opaque data field format must convey sufficient information for a client to select an appropriate implementation. For example, in a chat service, the opaque data field format may be a localized string which tells the user a group of people the implementation can chat with. For example, local area, MSN, AOL, bots and so on.