Identifier 

A distinction is made between simple identifiers and special identifiers.

Syntax

<identifier> ::= <simple_identifier> | <double_quotes><special_identifier><double_quotes>

simple_identifier, double_quotes, special_identifier

Explanation

Identifiers can be entered in uppercase/lowercase characters.

Reserved keywords must not be used in simple identifiers. Reserved keywords, however, can be specified in the form of special identifiers.

Double quotes within a special identifier are represented by two consecutive quotes.

Simple identifier: reservation

Special identifier: "ADD"