Coordination within noun phrases is a very general phenomenon in technical corpora. These noun phrases are composed of a noun head followed by one or more modifiers, and the coordination can affect either of the elements. The purpose is to make the noun phrases complete on both sides of the coordination, in order to improve recall in automatic interrogation. The tools are provided by intex: dictionaries, dictionaries of compounds, the software for writing transducers. First, coordinated noun-phrases are classified according to a typology. Then we present rewrite rules to handle the agreement of the modifier, the use of the possessive determiner, the repetition of the noun head within the modifier, the determiner or preposition zeroing in the right part of the coordination; and the construction symmetry within the noun phrases. Finally, we apply two rules and show the results. Not all the rules have yet been tested, but provisional conclusions can be drawn from this demonstration.