User, profile, and record type conditions in validation rules
Key Takeaway
Add user and record type conditions to a validation rule to aim it at certain users or record types. To exempt a user, add a condition inside the AND that is false for that user.
Validation rules can check who is saving a record and what kind of record it is, not just the values in its fields. Merge fields such as $User and $Profile, along with record type references, let you aim a rule at certain users or record types. They also let you exempt certain users from a rule.
How a validation rule blocks a save
A validation rule formula returns True or False. When it returns True, the user sees the error message and can't save the record.
To exempt a user, add a condition inside an AND that is false for that user, such as "the user is not the owner". One false condition makes the AND false, so the error can never fire for that user.