Short but important:
If a text (a course textbook, in this case) contains a graph or a box with important keywords, is the heading within that box capitalized? (e.g. “The Most Important Aspects of a Management Project”, followed by just five short keywords or sentence fragments.)
And do you capitalize the caption beneath it? (“Fig. 1: The Most Important…”)
What if it does not contain text, just a graph and a caption? Capitalized anyway? (“Fig. 1: Another One of These Graphs” or “Fig. 1: Another one of these graphs”)
Is there a difference between the US and GB?
And can anyone recommend me a good style guide on the internet?