This volume of Light Scattering Reviews describes some recent advances in a broad area of light scattering media optics. It is composed of three parts. The ?rst part is concerned with single light scattering by small nonspherical p- ticles such as crystals in clouds or suspensions of various cells. Most natural media are characterized by a variety of shapes and often a particular selection of particle shape is not representative of the ensemble of shapes encountered during measurements. This being the case, theoretical calculations are only of limited value and comprehensive experimental studies must be performed to e- cidate the question of optical response for a collection of particles having diverse shapes. The volume opens with the paper of Timothy Garrett, which describes a number of recent in situ airborne experiments related to the quanti?cation of optical properties of cirrus clouds. Min Xu and Alvin Katz discuss a novel statistical approach to deal with the light extinction and absorption properties of small nonspherical particles having a refractive index close to that of the host medium. In this case, van de Hulst's anomalous di?raction theory can be used. The new approach is applied to studies of bio-agent detection and monitoring. Michael Kahnert presents a comprehensive theoretical treatment of symmetries in linear boundary value problems. The use of symmetries simpli?es electrom- netic scattering problems to a great extent.