NIST Special Publication 800-122 defines PII as any information about an individual maintained by an organization, including (1) any information that can be used to distinguish or trace an individual’s identity, such as name, social security number, date and place of birth, mother’s maiden name, or biometric records; and (2) any other information that is linked or linkable to an individual, such as medical, educational, financial, and employment information.”
Retrieved and adapted from Guide to Protecting the Confidentiality of Personally Identifiable Information (PII), NIST SP 800-122. (2018). https://csrc.nist.gov/publications/detail/sp/800-122/final