Octal escape sequences in string literals have been deprecated since ECMAScript 5 and should not be used in modern JavaScript code.
Many developers may not have experience with this format and may confuse it with the decimal notation.
var message = "Copyright \251"; // Noncompliant
The better way to insert special characters is to use Unicode or hexadecimal escape sequences.
var message1 = "Copyright \u00A9"; // unicode var message2 = "Copyright \xA9"; // hexadecimal