(a) When Appropriate. Pertinent and significant legal authority may come to the attention of a party after a party has filed a brief, or after the appellate court has heard oral argument but before entering its decision. In these circumstances, the party may supplement legal authority that the party previously presented in the party's briefing by filing with the appellate court a supplemental citation of legal authority.

(b) Form. A supplemental citation of legal authority must clearly identify the page numbers of the party's brief that the party intends to supplement, and the relevant pages of the supplemental authority. The party must further state concisely, and without argument, the legal proposition supported by a supplemental citation.