Your blogger has long been fascinated by paratextual material in books. He is always very disappointed if, in picking up any old work, it lacks even ownership inscriptions. Manuscript notes in printed works are always fascinating. Indeed, student lecture notes are often written in margins or interleaves of printed works used as text books. Of course, paratextual material includes the congratulatory poems, addresses, and letters often printed with the text. Your blogger once had a plan to start a research project on paratextual material in historical Scottish law books. Just as he is an inveterate reader of acknowledgements and prefaces in modern books (which he is interested to find are ignored by many), so he always looks at the printed often prefatory paratext in historical law books. Such paratext can reveal much.
Such issues have occasionally been discussed in this blog: see https://www.elhblog.law.ed.ac.uk/2013/05/22/spottiswoodes-practicks/ https://www.elhblog.law.ed.ac.uk/2014/04/28/rare-books-of-scottish-provenance-los-angeles-law-library-sale/
https://www.elhblog.law.ed.ac.uk/2012/10/01/anton-schultingh-1659-1734/
