37 CFR 360.30: Amendment of claims.

Any claimant may amend a filed claim as of right by filing a Notice of Amendment during the statutory period for filing annual claims. After the expiration of the time for filing claims, a claimant may amend a filed claim as of right to correct the general description of the nature of the claimant's work(s), to fix typographical or other nonsubstantive errors in other portions of the claim, or to strike a claimant or interested copyright party that was erroneously included in a joint claim. No filer may amend a filed claim to add additional claimants or interested copyright parties after the expiration of the time for filing claims. All Notices of Amendment must be filed online through eCRB.