Chalking the Door: The Meaning of 20+C+M+B+YEAR

Why do Catholics have the symbols 20+C+M+B+YEAR written in chalk on or above their doors?

The symbols come from a Catholic blessing of the home connected to the Feast of the Epiphany.

Here is what they mean:

20+YEAR = The year of the blessing.
+ = The Cross
C = Caspar
M = Melchior
B = Balthasar

The letters can also stand for “Christus Mansionem Benedicat” which means “May Christ bless this house.”

The chalk symbols are nice reminders that you have asked for a blessing upon your home and all...