Form Data
Supported on: Firefox 74 or later, Firefox 68.6 ESR or later
Registry
HKLM
Software\Policies\Mozilla\Firefox\SanitizeOnShutdown HKCU
Software\Policies\Mozilla\Firefox\SanitizeOnShutdown Value name: FormData
Enabled: FormData = 1
Disabled: FormData = 0
Description
If the policy is enabled, form data is cleared when the browser is closed. If this policy is disabled or not configured, form data is not cleared when the browser is closed.