There isn't one uniform rule for headings: https://en.wikipedia.org/wiki/Letter_case#Headings_and_publication_titles https://en.wikipedia.org/wiki/Letter_case#H

There isn't one uniform rule for headings: https://en.wikipedia.org/wiki/Letter_case#Headings_and_publication_titles https://en.wikipedia.org/wiki/Letter_case#Headings_and_publi...