An Epiphany tradition at St. Mary's School - "chalking the doors"

Thank you Father Dave for asking Christ to bless our school this morning🙏
The Gospel tells us that the magi found Christ "on entering the house". The door to your home is a holy threshold. You can bless those who come in and go out by inscribing above the door in chalk: 20+C+M+B+20
The numbers stand for the current year, 2020. Tradition tells us that the letters stand for the names of the magi: Casper, Melchior and Balthasar. Adolph Adam points out that it may also mean "Christus mansionem benedicat" or "May Christ bless this dwelling". It is appropriate to bless your door in January - Janua means "door".