The constraint register
One table, REGISTER.md, and one page per entry. An entry is a published result that puts a price on faster-than-light travel or signalling: a theorem, an inequality, an instability, a hazard or a no-go argument. Each carries an id by family, a one-line statement, what it forbids or costs, the known escape hatches, and the citation.
Families:
| Family | Concern |
|---|---|
| CAU | Causality: signals to the past, chronology protection, the preferred-frame escape |
| ENE | Energy: the energy conditions, the theorems that superluminal travel violates them, the quantum bounds on borrowing |
| CON | Control: horizons, steering, the bootstrap problem, pre-built routes |
| STA | Stability: semiclassical instability of bubbles, throats and chronology horizons |
| HAZ | Hazards to crew and destination |
| LOR | Kinematics: what special relativity and wave propagation actually forbid, and the tachyon and tunnelling claims |
| WRP | The warp drive class: what a warp drive is, the shell classification and the dated state of the positive-energy argument |
| MAN | Leaving the manifold: what extra dimensions do and do not permit |
Verification marks in the citation column: ⚠ v1 means written from working knowledge in M0 and not yet checked against the paper. ✓ means the reference and the stated result were verified in M1. The matrix does not build on an unverified entry.
What is not on the register, by decision. Conservation of momentum. The two reactionless-thruster dossiers in the L6 bin (the EM drive and the Mach-effect thruster) fail on it, and say so in their own text, but it is not a faster-than-light constraint and would bite nothing else in the catalogue. The register stays the price list for one thing. Decided 2026-09-13.
Scoring vocabulary is in GRADING.md. Every dossier scores every entry here; the tables in the dossiers are the only source the matrix reads.
Page schema
One page per entry, filename the id in lower case (cau-1.md). H1 is the id and a short statement of the result, the italic hook is what it forbids in one line, and the metadata line carries **Kind:** constraint, **Family:** and **Last reviewed:**. Sections in order: The result, What it forbids or costs, Escape hatches, Who it bites (one line per dossier that scores against it, added as dossiers are written), Sources. tools/seed_constraints.py writes a skeleton for any id that has no page; the prose is then rewritten by hand.