The Institute's register lists objects manufactured in very large volume for which no published classification exists. It stands at 61 entries, with three withdrawals. Admission is governed by four criteria, all of which must hold. The criteria are easy to state and hard to apply, and this page sets out twelve cases where the Institute had to decide, with the decision and the reasoning in each.
Criterion 4 is the one that does most of the work and is the one most often forgotten. A classification that requires laboratory access describes the laboratory.
| Candidate | Decision | Criterion that decided |
|---|---|---|
| Rubber band | Admitted | All four. Width, thickness and unstretched length vary and nothing classifies them. |
| Drawing pin | Admitted | Variation. Point length and head diameter vary independently. |
| Bulldog clip | Admitted | Absence, narrowly. Jaw widths cluster commercially but no body has published the clusters. |
| Treasury tag | Admitted | Variation, in cord length and end-bar form. |
| Envelope | Refused | Criterion 2. Paper sizes are published and ratified. The envelope is classified. |
| Pencil | Refused | Criterion 2. Lead grading is published and in general use. |
| Staple | Refused | Criterion 2. Leg length and crown width carry designations issued by manufacturers and are consistent across them. |
| Bottle cap, crown type | Refused | Criterion 3. Made to one specification worldwide; there is nothing to vary. |
| Shoelace | Refused | Criterion 4. Length varies and is stated on the packet; there is no unstated dimension to observe. |
| Hair grip | Withdrawn after admission | Criterion 2. A trade classification was found after entry. Withdrawn, and the withdrawal published. |
| Bread-bag closure | Withdrawn after admission | Criterion 1. The Institute's volume estimate was wrong by an order of magnitude. The error was the Institute's. |
| The solitary fastener | Withdrawn, then reinstated unchanged | Criterion 1, disputed. Volume could not be established either way; the entry was restored on the argument that absence of evidence is not evidence of absence. |
Three lessons, and the second is the uncomfortable one.
Admission to the register is not a claim that the Institute will classify the object, and 44 of the 61 entries have no published scale. It records only that the object qualifies and that nobody has done the work. The register is a list of absences, not a programme.
Nor is admission a judgement that the object matters. The Institute has been asked to remove entries on the ground that they are trivial, and refuses: triviality is the condition under which classification goes undone, and a register of important unclassified objects would be empty.