Identifier (identifier). A distinction is made between simple identifiers (simple_identifier) and special identifiers (special_identifier).
<identifier> ::= <simple_identifier> | <double quotes><special_identifier><double_quotes>
simple_identifier, double_quotes, special_identifier
Identifiers can be entered in uppercase/lowercase characters. When you specify simple identifiers, upper and lower case are ignored, as the system always converts the identifier to upper case letters.
Reserved key words (reserved_key_word) must not be used in simple identifiers. Reserved keywords, however, can be specified in the form of special identifiers.
Double quotation marks (double_quotes) within a special identifier (special_identifier) are represented by two consecutive quotation marks.
Simple identifier: reservation
Special identifier: "ADD"