Programming Tools Guide
Chapter 3, C language compiler

Punctuators

Punctuators

Punctuators can be any one of the following:

 [   ]   (   )   {   }      ,   :   =   ;   ...
Depending on context, some of these punctuators can also be an operator or part of an operator. The pairs of punctuators [ ], ( ), and { } must match and appear in pairs after a source file is preprocessed. The punctuator # can only be part of preprocessing directive.