Transmissible Payload Types: A Receiver-Relative Taxonomy

A taxonomy of transmissible content types is presented: content types defined by what the receiver must functionally recover or instantiate for the transmission to succeed. The taxonomy applies to any bounded adaptive system with internal state that can receive, decode, and use information to change its own state or action. Five primitive receiver-relative content roles are identified — state, structural invariant, operation, symbol, and superposition. These are non-exclusive content roles, not mutually exclusive signal classes: a single transmission may instantiate several at once. The taxonomy is defined independently of physical medium, encoding, channel loss, or decoding implementation; it classifies content roles, not signal properties. Because classification is receiver-relative, the same physical signal may constitute a different payload type for different receivers whose functional codebooks require different steps. The five types constitute a completeness claim about possible content roles, not a prediction about which species or system uses which; four are observed in nature, the fifth is a non-classical theoretical extension.