The scope of PHI can be broad; however, medical information that an employer receives in its role as an employer (and not as the sponsor or administrator of a group health plan), is generally not PHI subject to HIPAA.
Alphabetic characters are the 26 letters of the alphabet. Numeric's are the ten digits. Alphanumerics are both. Some of the special characters on a standard keyboard do not work for usernames or passwords.
Non-printable character redirects here. For characters in text applications, see Non-printing character in word processors. In computing and telecommunication, a control character or non-printing character is a code point (a number) in a character set, that does not represent a written symbol. They are used as in-band signaling to cause effects other than the addition of a symbol to the text.