We define a class of languages () obtained by considering Regular languages, linear Constraints on the number of occurrences of symbols and Morphisms. The class presents some interesting closure properties, and contains languages with holonomic generating functions. As a matter of fact, is related to one-way 1-reversal bounded k-counter machines and also to Parikh automata on letters. Indeed, is contained in but not in , and strictly includes . We conjecture that .