Personal Identifying Information or Personally Identifiable Information (PII) is the information that permits the identity of an individual to be directly or indirectly inferred. An example of PII would be a persons Social Security Number, full name, passport number or email address.
Source: NCSD Glossary, CNSSI 4009, GAO Report 08-356, as cited in NIST SP 800-63 Rev 1
