The case of for open bibliographic data has been well made. The Open Knowledge Foundations' Bibliographic Working Group has established a set of Open Bibliographic Principles. The JISC Resource Discovery Taskforce has itself produced a comprehensive Open Bibliographic Data Guide, examining reasons for publishing through use cases and the wider context of open data elsewhere within the UK.
With such principles' and use-cases firmly established, one barrier to publishing open data lies in establishing the 'ownership' of a record, ensuring that as far as a library is aware, no existing license agreements with record vendors are breached.
COMET's in ital document on "Ownership" of MARC-21 records is designed to help identify where MARC-21 encoded metadata originates from and assist in establishing its provenance.
The documentation and underlying investigation was performed by Hugh Taylor, Head of Collection Description and Development at Cambridge University Library. Hugh is as familiar as anyone with the vast and varied dataset at the University Library. Given the size and scope of our data, the issues and examples raised will hopefully be of use to anyone else considering publishing of Open Data.
This guide is something of a work in progress, which we will revisit as COMET progresses. Next up is a brief summary of relevant licenses, aiming to provide an overview of what is allowed and not allowed with the array of data we have.
We would welcome feedback in the comments below.