What is the Mark Master's mark register and why is it kept?

The mark register historically served as the official record linking each member of a lodge to his own distinct mark 1. In operative practice, the registration of marks was essential for identifying the work of individual stonemasons, whereas among speculative members who did not engage in physical building, there was less practical necessity to maintain such detailed records 1.

Historical records, such as the 1670 register of the Aberdeen lodge, illustrate how these registers were kept and structured 1. In that early record, marks were assigned to both apprentices and passed craftsmen, with the same mark continuing to be used as a member advanced in grade 1. In the initial roll of forty-seven names, no two marks were exactly alike 1. The designs varied widely: some comprised odd or even points, some formed monograms of initial letters or equilateral triangles, and others depicted practical emblems such as a tailor's shears 1.

As the speculative element grew within lodges, the care taken in recording marks often diminished because non-operatives lacked the practical need for them 1. The operative masons, however, retained the mark book as a vital property of their trade; when the operative members left the Aberdeen lodge in 1781 to form a new lodge on the register of the Grand Lodge of Scotland, they took their mark book with them, after which the original lodge discontinued registering members' marks 1.