All user defined identifiers representing variables and functions should begin with an alphabetic character which will be lowercase. Examples:
entry, firstSum, trialTotal, x, y, z, displayResult, calculateCosts
All user-defined identifiers representing types should begin with an alphabetic character which will be uppercase. Examples:
Therms, Rates, ImaginaryNumbers
All user-defined constants, symbolic constants, should be represented by all uppercase characters. Examples:
UPPER_LIMIT, MAX_CHARACTERS, PI
All "built-in" identifiers representing variables, types, functions, etc. should be represented by all lowercase characters. Examples:
main, void, int, sqrt, if, while