The document is somewhat superceded by the 2013 IUPAC Nomenclature of Organic Chemistry recommendations, but the 2013 recommendations doesn't really differ from that document, and cites it when describing some of the quirks of carotenoid nomenclature. Adding the basics of carotenoid nomenclature should be easy. There are "only" 28 core structures, so it's probably simplest to just enumerate them. I'll try and look into it later this week.
Implementation notes: Supporting hydro prefixes on carotenoids will require special casing as the double-bonds cannot be treated as delocalised due to their implicit trans configuration. Supporting nor/seco would be useful for other natural products. Apo/retro only apply to carotenoids. The stereochemistry around atoms 16/17 must be indicated so that stereochemistry is implied if they are substituted.