A controlled vocabulary for Lightroom tagging based on IPTC and other sources of keyword hierarchies.
While IPTC is used as a starting point, it's more useful for news stories, so some of the categories don't map well to photographs.
IPTC subject codes ( http://www.iptc.org/site/NewsCodes/View_NewsCodes/#descrncd ) were used as the basis and the actual IPTC codes are inserted as synonyms.
Additional sources of keywords which have been incorporated into this scheme:
- William Beem's list: http://williambeem.com/tagging-photos-with-keywords/
- Controlled Vocabularly - Information visibly on the description here: http://www.controlledvocabulary.com/index.html