IDS research has thrown a good deal of light on issues not adequately treated in an earlier attempt to diagnose The Diploma Disease [Dore 1976]. The distinction between vocationally relevant credentials and the use of achievement tests in general education for ability screening is an important one: it is the latter which gives rise to the most serious problems. The presence or absence of centralised national examination systems, and the degree of bureaucratisation of employment are two of the features which greatly affect the use of diplomas. Finally, there is a good deal to be learned from the Chinese experiment in ‘delinking’ certificates and jobs.