Service-centric computing is developing and maturing rapidly as a paradigm for developing distributed systems. In recent years there has been a rapid growth in the number and types of processes being proposed to support aspects of SOC. Many of these processes require that services be modelled in a particular way and this puts great pressure on traditional notions of service specification, questioning the very nature of how services should be described for potential consumers. We present a technique for addressing this theoretical and practical bottleneck: faceted service specification. This allows different specifications to exist side-by-side if they are needed, yet places little obligation on the service provider to support specifications that are judged to be of little or no value. We show how faceted service specification is being used in the SeCSE project to support advanced service-centric system development activities.