Definition
PII (Personally Identifiable Information) is any data that can identify a specific individual, either on its own or combined with other information. Direct identifiers include name, email, phone number, physical address, and government ID numbers. Quasi-identifiers - like ZIP code, date of birth, and device fingerprint - are not unique on their own but often combine to single someone out (studies have shown that 87% of Americans are uniquely identified by their ZIP code, birth date, and gender together).
PII is not a synonym for "sensitive data." Under GDPR, there are also special categories requiring extra protection (health, biometrics, religion, political views) and pseudonymous data (identifiers that cannot be tied to a person without a separate key). In practice, treat most form-submission content as PII and design accordingly.
How SheetLinkWP relates to PII
SheetLink Forms treats every form submission as PII by default. The plugin offers optional IP redaction, field-level encryption for sensitive values, GDPR-compliant delete-by-email tooling, and a documented retention setting. The AI Lead Scoring and AI Analytics add-ons use anonymized aggregates rather than raw PII where possible. Your Sheet remains in your Google Workspace, so the ultimate data custodian is always you.