Different types of interactions between pairs of phonological rules can be converted into one another using three formal operations that we discuss in this article. One of these conversion operations, rule re-ordering (here called swapping), is well-known; another, flipping, is a more recent finding (Hein et al., 2014). We introduce a third conversion operation that we call cropping. Formal relationships among the members of the set of rule interactions, expanded by cropping beyond the classical four (feeding, bleeding, counterfeeding, and counterbleeding) to include four more (mutual bleeding, seeding, counterseeding, and merger), are identified and clarified. We show that these conversion operations exhaustively delimit the set of possible pairwise rule interactions predicted by conjunctive rule ordering (Chomsky & Halle, 1968), and that each interaction is related to each of the others by the application of at most two conversion operations.