The Containment Sigil

The Containment Sigil is a class of Sigil whose validated function is not passage, custody, or circulation but the delimitation of what may cross a given threshold and what may not. Unlike the Circulation Sigil, which moves a subject between floors, or the Sigil of Perpetual Custody, which voids rival claims upon a container, a Containment Sigil asserts only a boundary: inside, outside, and the narrow and heavily annotated strip between them. The class is enumerated in the Dewey-Sigil System as Sigil 11.02.δ, though its present designation dates from the Fourth Recension of 1,104 and supersedes three earlier numbers no longer in use.

Containment Sigils are administered jointly by the Sigil-Depths and the Office of Thresholds, an arrangement that has been described in two Concordances as "provisional" and in a third as "not to be revisited."

Function and calibration

A Containment Sigil holds a stated subject within a stated extent. The extent must be given in whole units and must not be left to inference; the Ninth Concordance, Annex 2, records that "a boundary unstated is a boundary disputed," a line now carved above the door of the Threshold Office at Floor 402.

Because containment alters a Sigil's ontological inertia, every Containment Sigil must be measured with a calibrated Sigil Placement Box both before and after validation. Readings are given in Standard Inertial Units (S.I.U.) by the Sigil-Depths, which maintains the primary record. A Containment Sigil reading below 3.4 S.I.U. after placement is held to be "advisory only," meaning the boundary it describes may be crossed by anyone who does not look directly at it.

Containment Sigils are not to be applied to stairwells. The prohibition appears without explanation in the Sixth Concordance, Clause 88, and has not been challenged in writing.

The Floor 402 leakage

In the winter of 1,137 a Containment Sigil of the second grade was placed upon the east reading room of Floor 402 to hold a collection of unindexed marginalia. The sigil was validated correctly and measured at 4.1 S.I.U. By the following spring, marginalia had been observed in the corridor, in the adjacent cloakroom, and — according to one affidavit filed with the Office of Thresholds — "in the coat of a visiting cataloguer, where it was not welcome."

The subsequent inquiry, convened under the Eleventh Concordance, found that the room's eastern wall had been re-plastered in 1,096 and that the Sigil had, without anyone's notice, been anchored to the plaster rather than to the masonry. The Sigil-Depths held that the boundary had therefore been drawn around a surface and not around a room, and that the leakage was technically correct behaviour. The Office of Thresholds disagreed, and the dispute was referred to the Concordance Arbitration Bench, which ruled in favour of the plaster on the ground that no one had told it otherwise.

"Where a boundary has been validly drawn, the Tower will respect it, including where the boundary has been drawn around the wrong thing."

— Concordance Arbitration Bench, ruling of 1,138, cited in Eleventh Concordance, Annex 9

The east reading room remains contained. The corridor does not.

The question of containment from within

There is long-standing disagreement as to whether a Containment Sigil acts upon the subject or upon the threshold. The Sigil-Depths maintain the former position: the sigil constrains the subject, and a subject so constrained cannot pass. The Office of Thresholds maintains the latter: the sigil constrains the threshold, and a subject may pass freely provided it does not cross the line, a position its critics have called "unusable."

The Seventh Concordance, Concordance 22, which governs Paradox Designations, is frequently cited by both parties and settles nothing, since it was drafted to describe sigils that fail rather than sigils that work. A minority view, advanced by the Readers' Chapter and not adopted, holds that the distinction is meaningless because the sigil, once validated, is the threshold.

Practically, the disagreement changes little. In 1,151 a Containment Sigil was placed on a document case at Floor 88 with the extent stated as "the case and its immediate surroundings," a phrase the Sigil-Depths rejected as unmeasurable. The case was contained. The surroundings were not defined, and a dispute over a hatstand continues.

Record and provenance

All Containment Sigils of the first grade are entered in the Primary Sigil Register, which is held in the Sigil-Depths and arbitrates questions of provenance. Lower-grade sigils are recorded locally, a practice that has produced a substantial and largely unread literature of local registers, of which the Floor 402 Register of Boundaries is the most cited and the least consulted.

Reclassification of a Containment Sigil requires a fresh placement reading and the countersignature of a Sigil Authenticator. The Dewey-Sigil System originally assigned the class Sigil 8.14.γ-β, a designation now reserved for containment sigils of disputed grade pending arbitration.

Known incidents

The record of Containment Sigil failures is short and repetitive. The principal holdings are the Floor 402 leakage of 1,137; the Bellwether Enclosure of 1,082, where a Containment Sigil placed on a bell was found after eleven years to have contained the sound and not the bell; and the Affair of the Second Door, in which two Containment Sigils of equal grade were placed on the same threshold by different offices and thereafter each refused to recognise the other.

The last remains unresolved. Both sigils are still in place. Visitors are asked to use the other door.