Network Working Group E.I. Ancona Request for Comments: 42 M.I.T. Lincoln Laboratory 31 March 1970 Message Data Types Proposal: We propose that the first eight bits of a normal message be reserved for a message data type. Adoption of this convention does not in any way signify agreement as to the actual data types to be used. It merely establishes the convention that the first eight bits of every normal message are not available for user data. Discussion: Socket Port | | | ____________ | V V / \ V / \ |=| /==| | -------(+)->|Y|-->|X|