~The New Liturgical Movement explains the Papal Formale that Pope Benedict wore on his cope on First Advent Vespers:
The formale (sometimes called also rationale, but not to be confused with the episcopal humeral proper to the Bishops of Eichstätt, Paderborn, Toul, and Cracow - see also Fr. Tucker's article with photos) is a morse used to join the two fimbriae of the cope. This insignia is reserved only to the Diocesan Bishop when he celebrates pontifically inside his Diocese.
Traditionally, the Sovereign Pontiff used three kinds of formalia: the precious one, used in the most solemn occasions, studded with gems; the ordinary one, shaped like a golden dove; and the penitential one, with three pinecones placed in a triangular pattern.
The penitential one wasn't used since 1969, but the Holy Father has decided to restore its usage right for the first Sunday of Advent.
What other treasures will we once again see?