alphanumeric

character A decimal digit or a letter (upper or lower case).

Typically, "letters" means only English letters (ASCII A-Z

plus a-z) but it may also include non-English letters in the

Roman alphabet, e.g., e-acute, c-cedilla, the thornletter, and so on. Perversely, it may also include the

underscore character in some contexts.

(1997-09-11)