This article describes the categorization of nominal concepts reflected in the honorific vocabulary of Tibetan. While better-known noun categorization systems, such as classifier systems, consistently categorize nouns according to perceptual categories such as shape and size, Tibetan honorific nouns are intrinsically categorized according to social and utilitarian parameters, i.e., in terms of the ways in which humans interact with their referents. It is suggested that this difference is explainable in terms of the function of the honorific system, which is specifically to express respect toward individuals.