This paper examines the implications of annotation programs, such as Annotea, for the development of the Dublin Core. Annotation programs enable multiple users, situated far apart, to comment on a Web-mounted document, even when they lack write access, through the use of annotation servers. Early indications suggest that the Dublin Core can significantly enhance the collaborative authoring process, especially if the full set of elements is used in a project that involves large numbers of users. However, the task of adapting DC elements and qualifiers for use in annotation threatens to increase the complexity of the scheme, and takes the Dublin Core far from its connections to traditional library cataloguing.