The broad field of conformational motion disorder in crystals is described with particular attention to the separation from the well known mesophases of liquid crystals and plastic crystals. Structure, thermodynamics and motion of a larger number of small and large molecules are discussed. Of special interest are the borderlines between smectic and high viscosity liquid crystals and condis crystals and between plastic crystals and condis crystals as complicated by pseudorotation, jumping between symmetry-related states and hindered rotation. This paper illustrates the wide distribution of...