Manual of Stack Maintenance 7th Edition

The Manual of Stack Maintenance (7th Edition) is the standing instructional text for the care, alignment, and doctrinal classification of stacks throughout the Tower. It is best known for its definition of a stack as "a contiguous set of shelving units, holding bays, or containment fields, containing related archival objects under a single classification sigil," a formulation that has been quoted in more subsequent proceedings than any other sentence in the maintenance literature and litigated more often than any of them. The current impression is the seventh, issued from the Scriptorium of the Lower Returns on 3-4-β-λ, replacing the sixth by suppression rather than revision — a distinction the preface declines to explain.

Scope and definition

The Manual governs stacks of every grade, from a single shelf of duplicate seals to the great lateral runs of the Delta stack. Its central article holds that a stack is constituted not by its shelving but by the sigil under which its contents are classified; a shelving unit without a sigil is, in the Manual's phrase, "furniture under sufferance." Clerks have long found this formulation inconvenient in practice. During the reclassification of the Hall of Perpetual Review, the sigil for one run of 214 bays was struck by error and not restored for eleven days, during which the bays were — by the Manual's own reasoning — no longer a stack, and the Department of Stack Integrity accordingly declined to inspect them. The department's note on the matter observes only that the bays were "not within remit during the interval."

The Manual is careful to distinguish a stack from a floor. Floors have numbers; stacks have sigils. Where a floor contains one stack, the two are often confused in correspondence, and the Manual recommends that clerks write the sigil first and the floor number in parentheses.

Maintenance schedules and the winter of the Long Recension

Maintenance is prescribed by interval, keyed to the Manual of Acceptable Strain, 11th Edition wherever the question is how much sag, deflection, or displacement a stack may carry before intervention. The Manual does not itself set tolerances; it refers the reader to the Strain Assessment procedure and directs that all readings be taken at the twelfth course of shelving, a convention inherited from the sixth edition and never revisited.

The seventh edition's most consequential addition was the requirement that all stacks over nine courses receive an annual vertical confirmation. Its first year of operation coincided with the winter of the Long Recension, when the survey corps was recalled to the Stairwell Sigma and confirmation lapsed on some four hundred stacks. The Manual of Vertical Cohesion was subsequently amended to excuse lapsed confirmation where the lapse is "general and administrative," a phrase the seventh edition does not use and has never adopted.

The dowel question

The Manual requires tactile corroboration of shelf seats, and on this point it defers without qualification to the standardized walnut dowel specified in Edition 12 of the Manual of Corporeal Confirmation. The deferral is repeated in Annex 2 of the Manual of Spirelocation Survey, 4th Edition, so that a single dowel now discharges obligations under three manuals at once. The Department of Stack Integrity has ruled, in an undated circular, that a dowel used for spirelocation survey may be used for stack maintenance in the same shift provided it is re-witnessed between uses.

"A dowel is confirmed once per course. A dowel confirmed at the twelfth course and carried to the ninth is not thereby confirmed at the ninth; it is merely present at the ninth."

— Manual of Stack Maintenance, 7th Edition, §41(c)

That clause is widely held to be the reason the department's inspectors work in pairs.

Dispute with the Manual of Vertical Cohesion

A persistent scholarly disagreement turns on which manual has precedence where the two conflict. The seventh edition, at §12, claims precedence over "all manuals touching the vertical disposition of stored matter." The Manual of Vertical Cohesion claims, at its own §2, to govern "any matter in which height is at issue," and does not except the maintenance text. The Concordance of Precedence, 3rd Recension resolves the question in favour of cohesion; the Concordance of Precedence, 5th Recension resolves it in favour of the earlier-issued text, which on the relevant dates is the seventh edition. The Bureau of Concordance Clarification has declined to say which recension is current, noting that the question is itself the subject of a pending clarification.

In practice the department inspects to whichever text yields the shorter report, a practice defended in the Manual of Subsidiary Procedures, 4th Edition as "validation of subsidiary items by internal consistency." The Manual of Validation Procedure, 4th Edition permits this, insofar as validation is there defined as "a certification of internal consistency" and nothing more.

Common faults and a note on ladders

The seventh edition catalogues the standard faults under a single schedule, of which the following are the most frequently cited in inspection returns:

• Sigil drift, in which the classification sigil migrates one bay per decade along the run.
• Course shear, most often at the twelfth course.
• Holding-bay encroachment, where a containment field exceeds its nominal aperture.
• Unauthorized reshelving by parties unknown, which the Manual treats as a fault of the stack rather than of the party.

Ladders are addressed in an appendix of four lines. The Manual's position is that ladders are not stack furniture and are therefore not its concern, though it adds that ladders found leaning against a stack should be recorded in the inspection return under "objects present." Clerks have asked for clarification of whether a recorded ladder is thereafter an object of the stack. None has been issued.

Status

The seventh edition remains in force. A Provisional Eighth Edition has been in preparation since the suppression of the sixth, and portions of it circulate in the reading rooms without having been validated under the Manual of Silent Procedure, Revision 9. The department's standing instruction is that the provisional text may be consulted but not maintained against. The Manual itself, at §1, states the matter plainly: "This edition is the edition."