1. alphabetic The letters A through Z and a through z. 2. alphanumeric The letters A through Z and a through z, and the numbers 0 through 9. control Any non-printable characters. The characters are used to control devices, separate records, and eject pages on printers. 4. numeric The numbers 0 through 9. 5. special Any of the punctuation characters or printable characters that are not alphanumeric. Include the space, comma, period, and many others.