 Many Christian processional banners are in the "vexillum form"; usually these banners are termed "labara" () after the standard adopted by the first Christian Roman emperor Constantine I replaced the usual spear point with the "Chi-Rho" symbol ☧.For example, a "vexillum" is used by the Legion of Mary as the term for its standards.A small version is used on the altar and a larger one leads processions.