A mysterious series of letters and numbers are appearing on the door frames of houses across the country. It may look like a string of code, or a particularly complicated scientific equation, but those worrying that the end is nigh, fear not – this is merely the resurrection of a centuries-old Christian tradition, currently being touted as ‘Holy graffiti’. The trend for ‘chalking the door’ – a blessing which is believed to have originated in, and spread from, Central Europe at the end of the Middle Ages – has seen an uptake in recent weeks as Britons look for a sense of community in a bid to lift spirits. Those partaking in the trend chalk their doors with the names or initials of the three wise men, or Magi, and the numerals of the New Year, connected with a series of crosses. The initials C, M, and B commemorate the Magi (Caspar, Melchior, and Balthasar), but also stand for the Latin prayer-request Christus Mansionem Benedicat: “May Christ bless this house.” In this way, this year doors are being marked with the commemoration: 20+C+M+B+21. The so-called ‘Holy graffiti’ has seen huge growth in England amid Covid-19 restrictions as Christians use the chalk to mark their doorway in a traditional Epiphany celebration. Rev Arwen Folkes, the Rector of St Peter’s in East Blatchington, Seaford, East Sussex, said she began the tradition in her parish last year, but said that this year it has become particularly poignant.