  This paper provides an abstract definition of some kinds of logics, called
diagrammatic logics, together with a definition of morphisms and of 2-morphisms
between diagrammatic logics. The definition of the 2-category of diagrammatic
logics rely on category theory, mainly on adjunction, categories of fractions
and limit sketches. This framework is applied to the formalization of a
parameterization process. This process, which consists in adding a formal
parameter to some operations in a given specification, is presented as a
morphism of logics. Then the parameter passing process, for recovering a model
of the given specification from a model of the parameterized specification and
an actual parameter, is seen as a 2-morphism of logics.
