DocumentationMathematicaThe Mathematica BookMathematica Reference GuideSome General Notations and Conventions
A.3.1 Function Names
The names of built-in functions follow some general guidelines.
The name consists of complete English words, or standard mathematical abbreviations. American spelling is used.
The first letter of each word is capitalized.
Functions whose names end with Q usually "ask a question", and return either True or False.
Mathematical functions that are named after people usually have names in Mathematica of the form PersonSymbol.