alphanumeric characters

(computer science) All characters used by a computer, including letters, numerals, punctuation marks, and such signs as $, @, and #. Also known as alphameric characters.

[Etymology: alphabet + numeric] Strictly any character that is in the alphabet else is a numeric digit, but often, by normal extension, another graphic, e.g. a familiar or other punctuation mark. Usually the space character is also included.