Organisms use chemicals to communicate various kinds of information. Here we discuss chemical-information systems that permit organisms either to identify other organisms as particular individuals or to be classified as a member of a particular kinship group. The material is presented from an integrated-systems perspective, a level of analysis that has been neglected in the study of kin-communication systems. After presenting a number of general concepts, we use honey bees as an exemplar for discussing encoding and decoding aspects of chemical recognition in the context of kin discrimination. We present new results on the variability of the cuticular signature in honey bee workers.