An agreed way of doing something. Like a conventionAn agreement on some decision that could be made several ways. For example, given a single bit, you could decide that 1 means "true" and 0 means "false," or you could decide the opposite. Similar in spirit to a protocol, but protocols usually deal with how something is done -- a step-by-step process, for example., except that protocols tend to be related to processes.
Inside the Internet of Things - Bryon Moyer Blog