This background paper to the MUS Symposium, from practice to policy has been written by Stef Smits, Mary Renwick, Daniel Renault, John Butterworth and Barbara van Koppen. In this background paper for the symposium, we aim to provide a synopsis of current work in two parts: the first part looks at key concepts and definitions on multiple-use of water and the second reviews existing work on multiple-use services, especially that carried out over the past 5 years since the earlier 2003 Johannesburg symposium.