This volume serves as a comprehensive cataloging effort to document and locate medieval manuscripts held within various British libraries. N. R. Ker, a distinguished paleographer and bibliographer, utilizes his extensive expertise to organize these primary sources by location. The work provides a systematic framework for scholars to identify and access specific manuscript collections across the United Kingdom, ensuring that these historical artifacts are cataloged with academic precision.

Scholars and librarians regard this series as a foundational reference tool for the study of medieval British manuscript culture. The text is noted for its high level of bibliographic density and remains a standard resource for researchers navigating institutional archives.