Roles which may be optionally attached to an ingredient.
type string
oneOf A USX peripheral label,eg “maps”
enum abbreviations, alphacontents, chron, cnc, contents, cover, foreword, glo, halftitle, imprimatur, lxxquotes, maps, measures, ndx, preface, promo, pubdata, spine, tdx, title
A role for story-based or video works, eg “teaching”
enum background, bridge, credits, diagram, gloss, illustration, introduction, scripture, teaching, timing
A role for PoD-type content, eg “printCover”
enum body, thumbnail
A label for story-type units
pattern ^unit\s.*\S$
A label for dictionary-type resources
pattern ^(name|sign|word|concept|place)(\s.*\S)?$
An x-role
pattern ^x-\S.*\S$