Tacit Tessera — human skills, real value
A tracked excavator in a yard, its boom and stick reaching across the frame

Sectors

Seven sectors, and the letter that leads a number.

A sector is the top division of the register. It sits above the track, and its letter is the first character of every Tacit Tessera number. Each sector keeps its own trades and its own family table, track by track, because the families that make sense on a pipeline spread make none in a drawing office. All seven sectors are open.

01What a sector is

A division, not a label.

A sector is not a tag on an entry. It is the division the entry is filed in, and it decides what the rest of the number can say. Within a sector, a family is the thing a skill set is about — the machine on the Hands and Machine tracks, the seat or the kind of record on the Records track — and a trade is the two-letter field the work is done in. A sector publishes which trades it uses. Family 0 is a Set on every track of every sector: several numbers licensed under one paper, each keeping its own count and its own name. A set is a shelf, not a stew.

The same trade code can appear in more than one sector, and the same family digit means different things in different sectors. That is the point of putting the sector first: the letter fixes which table the rest of the number is read against.

Sectors exist because the register takes in every kind of skill set. One list cannot hold a dozer, an estimating seat, a combine, an engineer's practice, a welding bench and a household. Seven can, and each one can be added to without disturbing the others. Inside Tacit Source a sector is a division of the register.

Seven sectors drawn as a row of machined plates, the top level of the Tacit Tessera register, above the track: Construction, Office, Agriculture, Professions, Trades and crafts, and Self, each with its one-line subject. All seven were opened together. SEVEN SECTORS · THE TOP LEVEL OF THE REGISTER OWNER'S ALL SEVEN OPEN TOGETHER C CONSTRUCTION MACHINE FAMILIES · HANDS, MACHINE, RECORDS O OFFICE THE EIGHT SEATS THE FIRST SHELF A AGRICULTURE ITS OWN MACHINE FAMILIES P PROFESSIONS A LICENSED PRACTICE T TRADES & CRAFTS A TRADE'S OWN WAY OF WORKING S SELF ONE HOUSEHOLD OPEN E ENTERPRISE AN OWNER-OPERATOR'S WAY OF RUNNING A BUSINESS THE SECTOR LETTER FIXES THE TABLE THE REST IS READ AGAINST A SECTOR IS A DIVISION INSIDE TACIT SOURCE, WITH ITS OWN STEWARD
Fig. — Seven sectors drawn as a row of machined plates, the top level of the Tacit Tessera register, above the track: Construction, Office, Agriculture, Professions, Trades and crafts, and Self, each with its one-line subject. All seven were opened together.
02The letter in the number

Sector · track · family · sequence · trade · edition.

A number reads in that order, ten characters in machine form, with a check character last: C H 3 001 MN · 1, machine form CH3001MN1Q. The C is Construction. The H is the Hands track. The 3 is the dozer family, in that sector. The 001 is the sequence within that family, issued in order and never reused. The MN is the trade — mining. The 1 is the edition. The check character is computed, never typed, so a mistyped number can be told from a real one before the register is asked.

The Tacit Tessera number as ten characters, grouped into six fields: sector, track, family, sequence, trade and edition, illustrated with C H 3 041 HD dot 3 — a Construction-sector, Hands-track example. Below, the same number in machine form as ten single-character cells; the first nine compute a Luhn mod 36 check character, shown as the tenth cell and never itself invented. THE TACIT TESSERA NUMBER · TEN CHARACTERS ILLUSTRATIVE GRAMMAR · NOT AN ISSUED NUMBER EXAMPLE C SECTOR CONSTRUCTION H TRACK HANDS 3 FAMILY e.g. 3 = DOZER 041 SEQUENCE ISSUED IN ORDER, NEVER REUSED HD TRADE HORIZ. DIRECTIONAL DRILLING · 3 EDITION THIS FROZEN VERSION MACHINE FORM · CH3041HD3… C H 3 0 4 1 H D 3 ? COMPUTED FROM THESE NINE · LUHN MOD 36 CHECK · COMPUTED BY THE REGISTRY, NEVER INVENTED SIX FIELDS, TEN CHARACTERS · THE SHAPE NEVER CHANGES WHEN A COMPANY IS RENAMED THE SECTOR LETTER LEADS EVERY NUMBER · NOTHING IS ISSUED YET
Fig. — The Tacit Tessera number as ten characters, grouped into six fields: sector, track, family, sequence, trade and edition, illustrated with C H 3 041 HD dot 3 — a Construction-sector, Hands-track example. Below, the same number in machine form as ten single-character cells; the first nine compute a Luhn mod 36 check character, shown as the tenth cell and never itself invented.

Only the register issues numbers, and a number not in the register is not a Tacit Tessera number, however it is written. Its seal can be checked at the address on the Card. How numbering works.

An oil filler cap and exhaust elbow with hose clamps inside an excavator engine bay
03What is filed today

Two sectors hold entries. Four are open.

Construction holds every Hands and Machine entry in the Book, and the machine's own manual set as a Records entry. Office holds the first eight seats of the Office sector and the Office Mosaic. Agriculture, Professions, Trades & crafts and Self are open, with nothing filed yet.

ESC H 1 001 CV · 1Ruth Iwasiuk —Excavator, civil…EDITION 1 · EXCAVATOR · CV

Ruth Iwasiuk — Excavator, civil earthworks
C · Construction · Hands EXAMPLE

SAO R 0 001 GN · 1Head office shelf — aRecords MosaicEDITION 1 · SET (MOSAIC) · GN

Head office shelf — a Records Mosaic
O · Office · Records · family 0, a Set

Every entry reads Specified. No capture session has been recorded, no operator has been signed, nothing has been metered and nobody has been paid.

04Who collects for a sector

A sector says where an entry is filed, not who brought it.

Steady Eddie and Strategic Agent require skill sets. Even Steven owns them. Tacit Tessera licenses them to OEMs and to AI. That chain holds in every sector. What changes from one sector to the next is which house collects there today: in Construction, Steady Eddie on Hands and Machine and Strategic Agent on Records; in Office, Strategic Agent. For the four open sectors no house collects yet, and one is named here when it does.

The mark on a tile is the mark of the house that collected the skill set — ES on a Hands tile Even Steven collected, SE on a Machine tile and on a hand Steady Eddie's Trainer brought, SA on a Records tile Strategic Agent collected. Even Steven's ownership of every skill set is said on the Card and on the licence. A sector page names the tracks it runs, prints its own family and trade tables from the register, and says which houses collect there.

05Opening a sector, a family or a trade

A decision of the register, written down.

A new sector, a new family or a new trade is opened by a decision of the register, recorded in the standard. Nothing is opened by use. A code, once issued, is never renamed and never reused; a retired family stays reserved. That is what lets a number written into a specification years ago still read the same way today.

Nothing was ever issued under a sector-less number, so nothing has been renumbered in anyone's hands. The Book simply carries the sector letter.

06The six

C · Construction

Machines, the work they do and the paper a job leaves behind. Tracks H, M and R. Construction

O · Office

A business's back office, built from the company's own records. Track R. Office

A · Agriculture

Farm machines, the seasons' records and the ground they are kept on. Tracks H, M and R. Agriculture

P · Professions

A professional's own practice, captured from the corpus they retained. Track R. Professions

T · Trades & crafts

A trade done by hand at a bench or a station. Tracks H, M and R. Trades & crafts

S · Self

A person's own household skills and their own papers. Tracks H and R. Self

The register itself is the Tacit Tessera Book, and any number in it can be checked at verify.