Thomr
Member
This can be bought from the headquarters of the Confraternity of St. James, at the praza da Quintana, by the Holy Door for 3 Euros and it says (according to google translate): The council of the Holy Apostolic Metropolitan Church Cathedral Basilica of Santiago de Compostela, located in the western region of Spain, all who shall see this letter of welcome, makes it known that D / a (proper name of the person requesting) has visited the Cathedral and the tomb of Glorious Apostle Santiago. On that occasion, the council, led the duty of charity while with joy, give the greeting of the Lord, through the intercession of the Apostle asked the Father to deign to grant spiritual wealth and material goods. Santiago bless him and be blessed. Given in Compostela, the Camino de Santiago Meta (date of the visit).
Perhaps not one for anyone who walks/cycles/rides to Santiago but it might be nice if you have any family who come to visit you when you arrive or for those who cannot physically manage the Camino.