This article presents an analysis of the enrichment, transformation, and clustering used by vendors Casalini Libri/@CULT and Ex Libris for their respective conversions of MARC data to BIBFRAME. The analysis considers the source MARC21 data used by Alma then the enrichment and transformation of MARC21 data from Share-VDE partner libraries. The clustering of linked data into a BIBFRAME network is a key outcome of data reuse in linked data projects and fundamental to the improvement of the discovery of library collections on the web and within search systems.