An ombrellino is, in its simplest form, a sunshade or parasol; but the form used in heraldry is taken from the achievement of the Pope. In that form, it’s more ornate, frequently ensigned with a cross, and has a handle resembling a tilting spear. The ombrellino became an element of the most common form of Papal augmentation of arms, as in the arms of Cesare Borgia, 1502 [Galbreath’s Papal Heraldry, p.30].
Since the ombrellino was used in Papal augmentation, its use in the Society must not be too allusive to that augmentation. In practice, that means the ombrellino may not be used in conjunction with keys in saltire.
Luciana Caterina de Borghese bears: Vair, an ombrellino gules.