This paper re-classifies over 2000 seal-impressions with at least one zoomorphic element drawn from the Corpus of Indus Seals and Inscriptions Volumes 1 to 3.2 (Joshi & Parpola, 1987; Shah & Parpola, 1991; Parpola et al., 2010, 2019). The classification is presented as supplementary data, S1. Tables 1, 2 and 3 explain the organisation of the data in S1. The tables and 8 figure charts reveal that Indus iconography is based on six principles of production design—formative, additive, extractive, subtractive, orientative, and associative. The associative principle illustrates the dynamics between the animal icon, the object in front, and other icons in a group or en file. The additive and extractive principles feed off each other, the latter being a device to deconstruct a compound design unit, the final product of an additive expression, and use that component-avatar in isolation or in a different context, in a way that the component and the compound recall each other. The compound-component genealogy is illustrated in figure charts. The classification yields at least 139 design units. 43 units have a singular expression on seals. The remaining 96 obtain from additive compounds on seal-impressions, hitherto not organised as such, even if recognised. The labels assigned to the component-avatars are non-interpretive and purely descriptive. However, there are a few instances where a label forces an interpretation and these are discussed case by case.