Francis, as true Crusader of Christ, signed himself with the sign of the
cross, by using chalk, end even by the design of his religious habit. He always kept the
cross before him, and when contemplating in caves, he would tie two sticks together that
he might be able to pray before the cross: We adore You, O Christ, and we bless You,
because by Your holy Cross, You have redeemed the world.
Hearing
the Pope Innocent III, proclaim that he needed to be signed with the Tau (which for
Innocent was directly linked to the notion of spiritual purity, represented by the
"white-robed" army of disciples in the Book of Revelation <see Revelation
7:2-14; Ezekiel 9:3-6; Exodus 12:7-14>), Francis took his challenge so seriously that
he would even sign his name using the Tau.
St. Francis marked all his letters and documents with Tau.
Even today spiritual daughters and sons of St Francis use this sign hanging on the neck,
mark documents by it, etc.