I have Sprung's books, and like them for quick reference/identification. Unfortunately, the books don't really contain *complete* care advice (simply not enough verbage for my liking).
Different tank setups will sustain different corals, and all offer different conditions/parameters - so IMO
, it's pretty difficult to assing a *hardiness* rating to a coral without knowing what conditions it will be placed in.
For a more "complete" coral reference (IMO
best coral reference book available [hobbyist-level]) - see "Aquarium Corals, Selection, Husbandry, and Natural History" - by Eric Borneman.