The Hallmark
The mark struck into work that passes
A Hallmark is struck in four parts, in sequence, exactly as British silver has been hallmarked since 1300. Each part answers one question: who built the work, against what standard, certified by whom, and when.
A struck Hallmark · Specimen
Specimen — Hallmarked under IDEA, version III, by the Oxford Internet Institute, for Practitioner S·H, in 2026. Illustrative only; not a Register entry.
AF-2026-0001-OII · specimen
The parts are always struck left to right in the same order, separated by a single gilt midline dot. Read together, they make a complete, attributable statement about a piece of work.
The Practitioner's Mark
Who built the work?
The first mark is the personal cartouche of the lead Practitioner who built and stands behind the work. Its initials and its shape identify the individual, not a firm; the mark accumulates, over a career, into a verifiable record of the Practitioner’s craft on the Register.
The Standard Mark
Against what standard?
The second mark names the Stewarded Standard the Engagement was assayed against, and its version — here IDEA, version III. Because the version is struck into the mark, the meaning of the Hallmark is fixed at the date it was made and does not drift as the standard develops.
The Assayer Mark
Certified by whom?
The third mark carries the cipher of the Accredited Assayer that performed the independent test — here OII, the Oxford Internet Institute. The cipher is also the final segment of the Engagement’s identifier, so the record itself names who certified, and who is accountable for the certification.
The Date Letter
And when?
The fourth mark is the Date Letter, a single letter in a cartouche whose shape and case fix the cycle while the letter fixes the year — here the round, italic lower-case a of 2026. The Date Letter is derived, never freely entered, so that a Hallmark cannot be back-dated.
The four-part composite
The cartouches, the cipher, and the Date Letter cycle, set out in detail.
For buyers
What a Hallmark means in procurement, and how to require it.
The Register
Every Hallmarked Engagement, with the Standard, the Assayer, and the date.