In this paper, some problems related to the design of decentralized controllers are considered. Due to information structure constraints on the systems, we are interested in determine when a gain-matrix corresponding to a control law can be designed having a required structure. To discuss this issue, we consider some generic classes of systems with different control strategies: optimal overlapping control, guaranteed cost control and H∞ control. For each one of them, two scenarios are supposed: state feedback and output feedback controllers. In this line, some new contributions are offered.