Other

CNIL recommendation

No collection of identifiers between websites (cross-site) or deterministically (CRM, unique ID (opens in a new tab));

Deletion of any other data that could lead to re-identification.

Solution

These two sentences don't concern a basic GA4 implementation, but they do remind us that we also need to delete any fields that could allow a user to be re-identified. We're talking about parameters such as user_id, email address, phone number, etc...