Feature-based models of sign language use distinctive features to describe the phonological structure of signs. We use near-minimal pairs and phonological phenomena like productivity and neutralisation in French Sign Language to show that the feature [web], which refers to the webbing part of the fingers, should be (re)introduced into the list of phonologically active features. In discussing potential cases of [web] in other sign languages and the impact on the shape of phonological inventories, we first offer an account of [web] in terms of a location feature in line with most traditional feature-geometry models. We then offer some speculations on why a more uniform characterisation of [web] and the features in the same subclass in terms of the orientation type results in more economical models.

This article examines a turning point in the history of the theory of phonological distinctive features. In Morris Halle’s (1959) The Sound Pattern of Russian, features are organized into a contrastive hierarchy designed to minimize the number of specified features. Redundancy rules, however, ensure that the resulting underspecification has no real phonological consequences and, in subsequent generative approaches to phonology, contrastive hierarchies were largely abandoned. We explore how Halle’s hierarchy would have been different if it had been based on phonological patterns such as voicing assimilation, and show that this reorganization makes plausible predictions about other aspects of Russian phonology. We conclude by pointing to recent work in which the concept of a contrastive hierarchy has been revived, illustrating the range of phenomena that this theoretical device can account for if minimizing specifications is not the primary concern.

It is argued that proxy relations between feature-defining and enhancing gestures in the phonetics can become phonologized. The article proposes Optimality-theoretic markedness constraints, which are grounded in phonetic enhancement and which can compel a delinked/unparsed/floating feature to be realized with another feature (or prosodic element), giving the impression of featural transmutation. Among the phonological phenomena revisited are incomplete neutralization, devoicing, vocalization, and debuccalization.