Unified Theories of Cognition: Encoding Productions

From Unified Theories of Cognition, pp. 196-197:
The total system consists of more than P to C to M. There is a set of productions called encoding productions (E-productions) and another set called decoding productions (D-productions). These productions are identical in form and structure to the productions of central cognition (which can be called C-productions where needed). They differ in being entirely free of the goal context stack. For them there is no such thing as the decision cycle, running to quiescence, or impasses -- they fire at will. In contradistinction, cognitive productions are tied to the goal context stack by the connectivity constraint. Each condition must either match a goal-context element or match an element that links (perhaps through an explicit chain) to a goal-context element. Encoding and decoding productions are distinguished from each other only by the functions they perform.

More about encoding.