The Supreme Court shall by rule provide for the filing of briefs in all causes appealed to the Court of Appeals or Supreme Court. The brief of appellant shall set out particularly each error asserted and intended to be urged for the reversal, vacation, or modification of the judgment, decree, or final order alleged to be erroneous, but no petition in error or other assignment of errors shall be required beyond or in addition to such requirement. The Court of Appeals or Supreme Court may at its option consider a plain error not specified in appellant’s brief.