A character string literal is a string of printable characters.
    The maximum length of a character string is 65,536 characters.
    The printable characters are:

    o  Uppercase alphabetic characters (A-Z)

    o  Lowercase alphabetic characters (a-z)

    o  Numerals (0-9)

    o  The following special characters:

                ! @ # $ % ^ & * ( ) - _ = + ` ~

                [ ] { } ; : ' " \ | / ? > < . ,

    o  Any other characters that are part of the Digital
       Multinational character set

    o  Japanese characters: Kanji, as defined by the JIS X0208:1990
       standard, and Narrow Katakana, as defined by the JIS
       X0201:1976 standard

    You must enclose a character string literal in a pair of either
    single or double quotation marks. Quotation Marks in Character
    String Literals shows the valid use of quotation marks in
    character string literals.

    Table 5-5 Quotation Marks in Character String Literals

    Character String Value
    Expression                   Value

    "JONES"                      JONES

    'JONES'                      JONES

    "JONES'                      [invalid]

    "''''"                       ''''

    "'''''                       [invalid]

    'My name is "Lefty".'        My name is "Lefty".

    'My ''handle'' is "Lefty".'  My 'handle' is "Lefty".

    CDO usually treats uppercase and lowercase forms of the same
    letter as the same character. However, it preserves the case
    distinction when doing comparisons of character strings; for
    example, NAME = "JONES" and NAME = "Jones" yield different
    results.

    o  Begin and end a character string literal with the same type of
       quotation mark.

    o  To include a quotation mark of one type in a character string
       literal, enclose the literal in quotation marks of the other
       type. For example, to include double quotation marks in a
       character string literal, enclose the character string in
       single quotation marks.

    o  If a quotation mark appears in a character string literal
       enclosed by quotation marks of the same type, use two
       consecutive quotation marks for every one you want to include
       in the literal. This technique is necessary if you want to
       include quotation marks of both types in a single quoted
       string.