This paper provides a detailed description of the general design space for metadata storage capabilities. The design space considers issues of metadata identification, typing and representation, dynamic behavior, predefined and user-defined metadata, schema discovery/update, operations, API packaging/marshalling, searching, and versioning. The design space is used to structure a retrospective analysis of the three major alternative metadata designs considered during the design of the WebDAV distributed authoring protocol. Deployment experience with WebDAV properties is also discussed, with the most successful use occurring in custom client/server pairs and in protocol extensions.