The original T1.232-1996 provided information on a wide range of topics germane to the design of Human Machine Interfaces (HMIs).1 Subsequent work went into more detail resulting in three ITU-T standards referenced in this document. These three ITU-T Recommendations should be employed directly for HMI design in telecommunication management applications. 1 The superseded T1.232-1996 document is available upon request from <docenter@atis.org >.