Recently we mentioned the
Franciscan shrine of La Verna, where St. Francis of Assisi is said to have received the stigmata, and there, while featuring the splendid 16th century
parato di Pentecoste, I noticed a rather different looking vestment which my Franciscan contact also pointed to, what is locally referred to as, the "tonacella per novizi" (the tunicle of novices), used specifically by the Franciscan novices within the context of processions.
Here is a historical view of this usage in the context of a festive procession following Vespers at La Verna.
Here are some images of this
tonacella in use today: