The flagged-for-chapter field I added recently should actually have been a one-to-many, so I've now done that, which involves a quick SQL script to build the two required tables, and changes to the local_classes.php file to add the Chapters table as an editable one and the one-to-many field in the documents table (doc_chapters). There's some text data in the old field to be transferred; once JW has done that, I'll remove the old field. Tested first in dev, and migrated to live.