The Brennholt Institute of Applied Taxonomy maintains a register of manufactured objects produced in very large volume for which no published classification exists. At 1 September 2026 the register holds 61 entries. It is the Institute's working list: an object enters the register when it meets four admission criteria, and it leaves when a classification for it is published by anyone, including the Institute itself.
The register exists because the absence is systematic rather than accidental. Objects acquire classifications when someone needs to compare them — for safety, for load, for interchange, for resale value. An object that is cheap, interchangeable and consumed without record acquires none, no matter how many are made.
The stability criterion is the one that rejects most candidates. The Institute's position is that a taxonomy of a moving object describes a moment, and that the register is meant to hold objects whose classification would still be true in twenty years.
| Entry | Object | Admitted | Status |
|---|---|---|---|
| R-001 | Office paperclip | 2023 | Left the register 2025: seven-class system published |
| R-004 | Adhesive filing tab | 2023 | Open |
| R-007 | Drawer liner, cut sheet | 2023 | Open |
| R-012 | Terrestrial globe stand | 2024 | Left the register 2025: typology published |
| R-018 | Bread-bag closure clip | 2024 | Open |
| R-023 | Shelf-support peg | 2024 | Open |
| R-031 | Elastic band, office grade | 2025 | Open, contested |
| R-038 | Curtain hook, plastic | 2025 | Open |
| R-044 | Paper tablecloth clip | 2025 | Open |
| R-052 | Key tag, blank | 2026 | Open |
| R-061 | Boot-tread cleaning mat | 2026 | Open, provisional |
Three entries have left the register since 2023. Two left because the Institute published a classification for them. The third, R-009, a plastic cable clip, left in 2024 when a trade association was found to have published a size table in 1991; the Institute records the withdrawal and the year of the document it had missed. Brindlecott has written that this is the most useful entry in the register's history, because it is the only one that demonstrates the register can be wrong.
The paperclip left the register in 2025, and the Institute continues to present it first. Its absence of a classification could not be explained by obscurity, by cost of access, or by difficulty of measurement: the object is everywhere, costs almost nothing, and can be measured with a caliper in under a minute. No national standards body has ever ratified a diameter class for the office paperclip, and Brindlecott's seven-class system remains the only published attempt. Every other entry in the register is argued by analogy to it.
R-031, the office elastic band, is contested on the observability criterion. The Institute's review panel argued on 3 March 2026 that the properties that would classify an elastic band — tensile recovery, ageing rate, set under sustained load — cannot be measured without destroying the sample, and that the entry therefore fails criterion three. Brindlecott maintains that cross-section and free length are sufficient classifying properties and are measurable without destruction. The entry is held open under protest, which the register records in the status column.
R-061, the boot-tread cleaning mat, is marked provisional because the volume figure has not been established. The Institute has an estimate of stock in use and no estimate of annual production, and prints both facts.
The taxonomist of Kettering rejects the register's design outright, on the ground that a list of absences is not a research programme and cannot be falsified. Brindlecott's reply is that the register has been falsified once, at R-009, and that this is one more time than most programmes manage. Neither has replied since 2025.