50 Your ancestors, whose magnificent deeds you commemorate this year with festivities, surrounded their leaders and knights, waving flags signed with the cross, and either accompanied them, or - if this was not possible - followed them with prayers, a zealous good will, and their assistance. So too you should consider yourselves highly honored if you have contributed to the growth of the sacred missions your sons, your prayers, your aid.
Source: Saeculo Exeunte Octavo (Vatican.va)