Abstract. Control sets on grammars are extended to depth-first derivations. It is proved that a context-free language is generated by the depth-first derivations of an arbitrary context-free grammar controlled by an arbitrary regular set. This result is sharpened to obtain a new characterization of the family of derivation-bounded languages: a language L is derivation bounded if and only if it is generated by the depth-first derivations of a context-free grammar G controlled by a regular subset R of the Szilard language of G. The left-derivation-bounded languages are characterized analogously using leftmost derivations. It is proved that a grammar G is nonterminal bounded if and only if the Szilard language defined using only the depth-first derivations of G is regular. Finally, it is proved that if a family of languages C is a trio, a semi-AFL, an AFL, or an AFL closed under k-free substitution, then the family of languages generated using arbitrary context-free grammars controlled by members of C is full, is closed under reversal, and has the closure properties assumed of C.