I'm a professional travel photographer with 30 years of experience. I've been travelling for many years, and has visited all 7 of the 7 continents and 148 countries to date. I'm represented by Getty Images, the world's top Travel Photography stock image library, but also have my own Travel Photography website at www.gnomeplanet.com to showcase and market his favorite digital images, and to provide his popular Free Photography Tutorials, Photographer Tips, Articles, Links, and other Photographer Resources.
My www.photo-keywords.com has lots of articles on all aspects of hierarchical tab-indented lists, plus many tutorials on error-catching, sorting techniques, explanations of hierarchy, and suggestions for making your own keyword lists. Also lots of free keyword lists, and my own keyword catalog.