An important topic in formal concept analysis is to cope with a possibly large number of formal concepts extracted from formal context (input data). We propose a method to reduce the number of extracted formal concepts by means of constraints expressed by particular formulas (attribute-dependency formulas, ADF). ADF represent a form of dependencies specified by a user expressing relative importance of attributes. ADF are considered as additional input accompanying the formal context 〈
〉. The reduction consists in considering formal concepts which are compatible with a given set of ADF and leaving out noncompatible concepts. We present basic properties related to ADF, an algorithm for generating the reduced set of formal concepts, and demonstrating examples.