Guy Goodwin-Gill gives a talk for the Refugee Studies Centre podcast series. In 1977, as national refugee status determination procedures were gaining new life, State members of UNHCR’s Executive Committee asked the Office to provide guidance on the interpretation and application of the 1951 Convention/1967 Protocol. The outcome was the 1979 UNHCR Handbook, still widely cited in courts around the world, but substantially unchanged notwithstanding successive ‘re-issues’. Following adoption of its Agenda for Protection in 2000, UNHCR sought to keep up with jurisprudential developments and emergent issues by publishing supplementary guidelines, for example, on exclusion, gender, social group, and children; these were mostly drafted in-house, like the original Handbook, and without any formal input from States or other stakeholders. Following criticism of its 2013 guidelines on military service, however, UNHCR began to consider how external input could be usefully and effectively managed, for example, through the circulation of drafts for comment. Authoritative and influential guidelines will need a solid methodology when it comes to synthesizing best practice and pointing the way ahead, and UNHCR cannot just rely on its statutory and treaty role in ‘supervising the application’ of the 1951 Convention. In some respects, its task is analogous to that of the International Law Commission, incorporating both codification (identifying where States now see the law) and progressive development (showing how the law should develop consistently, if protection is to keep in step with need). So, what are the issues on which further guidance is needed today? What, if any, are the limits to interpretation, and when are new texts required? In drafting guidelines, who should be consulted? And how should others’ views and analysis be taken into account?