Keywords are words that have a special meaning to the Resource Compiler. In a statement, keywords specify the resource type, the directive, the memory options, and the beginning and ending of nested statements. You can use keywords only as specified in the statement syntax.
Keywords, except for those specifying directives, can be any combination of uppercase and lowercase letters. Note that the left and right braces, { and }, are reserved characters. You can use them in place of the BEGIN and END keywords, respectively.