Check Point HARMONY R81 Administration Manual page 345

Alert User Only - If a user enters a corporate passwords in a non-corporate site,
l
the user gets an alert.
n Protected Domains - Add domains for which Password Reuse Protection is enforced.
Harmony Endpoint keeps a cryptographic secure hash of the passwords used in these
domains and compares them to passwords entered outside of the protected domains.
After you configure the settings, click OK.
R81 Harmony Endpoint Server Administration Guide | 345
Zero Phishing Settings