FRCP 15(c)
Definition
Allows an amendment changing the name of the party the claim is asserted against to relate back to the time the original pleading was filed, even when the statute of limitations has already run. Relation back is allowed under this rule only if the claim in the amendment arose out of the same transaction as that asserted in the original pleading. Also, within 120 days of the original pleading being filed, the new party brought in by the amendment must either (1) have actual notice of the suit so he will not be disadvantaged in defending himself or (2) know or should have known that the suit would have been brought against him but for a mistake.