There are two ways to define a semantics for process algebras: either directly by means of an equivalence relation or by means of a preorder whose kernel is the desired equivalence. We are interested in the relationship between these two presentations. Using our characterisation of the behaviour preorders by means of simulations up-to we were able to generate the canonical preorders corresponding to each behaviour equivalence. The axiomatizations of these preorders can be obtained by adding to the axioms of the equivalence that of the appropriate simulation. Aceto, Fokkink and Ing