The content model for msItem currently explicitly references bibl and listBibl. It would be more appropriate to reference model.biblLike. This would permit inclusion of biblStrruct. There is a significant real case for projects such as the BVH at Tours, where msDesc is used to document copy-specific information for items also containing full bibliographic descriptions. At present, they embed a biblStruct inside a <p> inside <msContents> which is not very pretty. And won't work if they ever find a printed work containing two distinct bibliographic items.