This article introduces the JHOVE2 format characterization tool, comparing it with its predecessor JHOVE, the first characterization framework developed and used by international digital library programs and preservation repositories. Besides going into JHOVE2 development and specifications, it explains why characterization is essential in digital preservation workflows and emphasizes the addition of an assessment functionality which allows the repository to determine the acceptability of an object based on locally defined policies. Appeared in: The International Journal of Digital Curation. Issue 3, Volume 4, 2009
