Concordance of Aperture Regulation

The Concordance of Aperture Regulation is the primary legal instrument governing Aperture Regulation within the Tower, a living document comprising over 700 clauses distributed across 12 primary annexes. It defines apertures as any permanent or semi-permanent opening between floors, sets the procedural standard for their establishment and interdiction, and specifies — often at cross purposes with itself — who may certify them. Its oldest continuous clauses date, by the reckoning of the Librarians, to the recension of the eleventh winter of the Fourth Ascension, though the preamble to Annex A concedes that "the numbering of the present edition reflects convenience rather than descent" (Concordance of Aperture Regulation, Annex A, Preamble). The document is amended more often than it is read and cited more often than it is amended.

Structure and the twelve annexes

The Concordance is not a single bound volume but a sequence of recensions, each annex maintained by a different scribal hand and corrected, on average, every eleven years. Annexes A through D are considered primary, and of these Annex D is the best known for its section on Stairwell 44, whose governance it entirely determines. Annex C-7 carries Aperture Regulation 7, the sub-regulation controlling resonance spillage, and is the clause most frequently disputed at the Aperture Regulation Board.

The remaining annexes address matters that resist summary. Annex F concerns the reporting of apertures observed in error; Annex H, the restoration of an aperture to a condition it never held; Annex L, the sealing of doors that were never intended as apertures but are argued to have become so. Annex L is short and largely ignored, though the Clerks of the Aperture invoke it more often than any other annex, usually in January.

Annex 9 and the phase cycle

Aperture Regulatory Annex 9 establishes that Aperture 317-1 cycles between Phase Theta and Phase Iota on a 27-hour cycle, and is the only annex whose text is printed with a table of intervals. The table has never been corrected, though a later recension revised the closing line of the same annex to read "the phases are, for the purpose of the record, what the Board reports them to be" (Concordance of Aperture Regulation, Annex 9, closing paragraph). Custodians at Spire 91 maintain that the revision was drafted to silence a dispute they had raised; the Board has never accepted that the revision addressed their objection.

History and revision

The Concordance's early history is reconstructed almost entirely from marginalia. The Seventh Council of Annotators produced, in the space of one season, the recension now known as the Twelfth Concordance, which rearranged the annexes alphabetically and thereby severed Annex D from the material it references. The rearrangement stood for sixty years before Concordance 14 restored the original order with a note that has since become the standard formula for apology in the Tower's legal writing: "The Commissioners regret the interval" (Concordance 14, Explanation of Restorations).

Amendment procedure under the current edition is straightforward but rarely completed. A proposed clause must be entered in three annexes simultaneously; if any annex goes unentered for a full cycle, the proposal lapses. The Registry of Amendments records 2,114 lapsed proposals between the Twelfth Concordance and the present day, of which 41 have been reintroduced under different annexes and none has since passed.

Conflicting rulings

The Concordance's most visible difficulty is its overlap with Regulation 44-B: Contaminants of Certainty, which governs certainty gradients and is said, in the language of the Aperture Concordance's own Annex A, to "operate in parallel without prejudice to either instrument." That clause is itself cited as the ground of the dispute, since a parallel operation without prejudice makes it impossible to determine which instrument takes priority when an aperture appears both as an opening and as a locus of certainty. The Office of Epistemic Hygiene holds that Regulation 44-B controls; the Aperture Regulation Board holds that it does not.

The contradiction does not end there. Annex D, governing Stairwell 44, requires that apertures there be sealed during the hours between the second and fourth bells, where Aperture Regulation 7 requires sealing whenever resonance spillage is present, regardless of hour. On the twenty-second of the ninth month, in the winter that produced the Seventh Recension of Annex D, the two clauses were applied simultaneously to a single opening, which was accordingly sealed twice and, by the Board's later account, "opened, briefly, once" (Minutes of the Aperture Regulation Board, entry for the same date). The passage has never been further explained.

Criticism and the practical notices

Spiral 19, Aperture Delta has twice petitioned against the Concordance on the ground that Annex 9's cycle cannot be observed at that aperture, since the Delta's aperture does not cycle. The petition was refused on the procedural point that the Concordance does not provide for apertures that do not cycle. The Clerks of the Aperture have made the same observation in their annual returns without success.

The Concordance is also the closest thing the Tower has to a visitor's guide. A person entering a regulated aperture for the first time is required, under Annex D and by long habit elsewhere, to state their floor of origin aloud before crossing; and by the standing rule of the Board, nothing may be carried through an aperture in a container that was not itself catalogued on the floor it entered from. The rule appears once, in a footnote to Annex C-7, and is enforced.

"The Concordance is an instrument of restraint, not of clarification; those who come to it for answers should first be sure they have come to it for the right question."

— Twenty-Ninth Concordance, Preface to the Annexes

The present edition remains in force, as all editions do. Copies are held at the Registry of Amendments, the Aperture Regulation Board's own scriptorium, and — under conditions Concordance 14 describes as "not to be inferred" — at Spire 91.