Naming

Darn, decade (note the singular :P) of experience in the programming industry, and I still don't have a hard and fast rule on names in program like in Firstname vs First Name.

Correct form is First Name, so that gives us these valid names for the program: first_name, firstName, FirstName; words have boundary. Hence these are invalid: firstname, Firstname.

It's a different rule on Username though, correct form is Username, not User Name.These are valid names for the program: username, Username. These are invalid: user_name, userName, UserName.