Naming convention for attributes/functions/menus

In programming there are ex. PascalCase and CamelCase and more conventions.

In the SIGCHI Conference Proceedings Format subsections and sub-subsections starts with initial letters capitalized, but a word like the or of is not capitalized unless it is the first word of the heading.

Is there a naming convention for attributes, functions and menus displayed to the user, to maximize usability? From what I've seen so far, large sites use the name conventions of SIGCHI.

I've attached two pictures. First picture is an original picture of a Facebook menu, the second is an altered version.