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+# The Latin Bridge
+### TheRON — OTIVM / CIVICVS / TESSERA Stack
+### Purpose: Connect research vocabulary (Layer 2) to code tokens (Layer 3) via Latin
+### Status: Living document
+### Date: 2026-04-28
+
+---
+
+## 0. Why this document exists
+
+The research brief (`research-brief-roman-venture.md`) instructs ChatGPT to
+use Latin where academically defensible. The terminology document
+(`terminology.md`) defines the three-layer vocabulary and the code tokens.
+
+This document is the bridge between them.
+
+When ChatGPT returns a research result using a Latin term, this document
+tells the developer:
+- Whether that term has been admitted to the canonical vocabulary
+- What code token it maps to
+- What it precisely means — not a gloss, but the full semantic content
+- What it does not mean — the boundaries of the term
+- Why Latin was chosen over English for this concept
+
+When a developer encounters a Latin term in documentation or UI text, this
+document tells them which code token to use in the corresponding database
+column or API parameter.
+
+This document does not duplicate `terminology.md`. It deepens it.
+Where `terminology.md` lists terms, this document explains them.
+
+---
+
+## 1. The admission standard — restated precisely
+
+A Latin term is admitted to the canonical vocabulary when it satisfies
+all three of the following:
+
+**Test 1 — Period-authentic.**
+The term was in documented use by Romans of the relevant period
+(approximately 1st century BCE to 1st century CE) in the relevant
+context (commercial, civic, or social life of a working MERCATOR).
+Terms from legal texts, literary sources, or inscriptions are all
+admissible if the context is appropriate. Terms whose only attestation
+is in later, ecclesiastical, or medieval Latin are not admitted without
+explicit note.
+
+**Test 2 — Semantically denser than the English equivalent.**
+The Latin term carries information that the nearest English equivalent
+does not carry without additional explanation. The test is practical:
+if you can replace the Latin with an English word and lose nothing, use
+the English. If replacing it requires a phrase, a footnote, or a
+qualification, the Latin earns its place.
+
+**Test 3 — Scope-bounded.**
+The term cannot be applied to a different period or culture without the
+misapplication being immediately visible. This visibility is a feature —
+it prevents vocabulary from bleeding across periods and erasing the
+distinctions the simulation depends on.
+
+**The consequence of passing all three tests:**
+The Latin term becomes the canonical human-facing label for that concept
+in the Roman layer. It appears in UI text, in journal entries, in
+documentation prose, and in research briefs. It does not appear in code
+tokens, database column names, or API parameters — those use the
+period-neutral Layer 3 tokens defined in `terminology.md`.
+
+---
+
+## 2. Admitted terms — full semantic entries
+
+Each entry below provides the full semantic content of an admitted Latin
+term: what it means, what it does not mean, why it was chosen over
+English, and what code token it maps to.
+
+---
+
+### NEGOTIVM
+**Code token:** `venture`
+**Literal:** business, affair, occupation, work
+**Opposite:** OTIUM
+
+NEGOTIVM is not merely "business" in the modern sense. It is the active,
+engaged, outward-facing dimension of a Roman's life — everything that
+demands time, attention, and presence in the world. Commercial activity
+is the most obvious form, but NEGOTIVM includes legal proceedings,
+political obligations, military service, and any other demand that pulls
+a person away from OTIUM.
+
+For the MERCATOR, NEGOTIVM is the commercial venture — the ITER from
+warehouse to market, the negotiation of price, the management of cargo.
+But it carries an implicit moral weight that the English "business" does
+not: NEGOTIVM was understood as the necessary but lesser part of life.
+A life of pure NEGOTIVM, without OTIUM, was considered incomplete.
+
+**What it does not mean:** It does not mean a single transaction.
+A NEGOTIVM is a bounded undertaking — it has a beginning, an end, and
+a purpose. Individual transactions within it are EMPTIONES (purchases)
+or VENDITIONES (sales).
+
+**Why not "venture" in the UI:** "Venture" is correct as the code token
+because it is period-neutral. In the UI, NEGOTIVM is used because it
+carries the moral and social weight that "venture" does not. When the
+player reads "begin a new NEGOTIVM," they are being told — even if they
+do not yet understand why — that what they are doing has a cost beyond
+denarii.
+
+---
+
+### OTIUM
+**Code token:** `interval`
+**Literal:** leisure, rest, ease, peace
+**Opposite:** NEGOTIVM
+
+OTIUM is the most misunderstood term in the Roman vocabulary. It is not
+idleness. It is not vacation. It is not the absence of work.
+
+OTIUM is the deliberate, purposeful withdrawal from NEGOTIVM for the
+cultivation of the self and the fulfilment of social obligations that
+cannot be conducted in the marketplace. Cicero wrote his philosophical
+works during OTIUM. Generals retired to their estates for OTIUM.
+A MERCATOR took OTIUM to maintain his CLIENTELA, participate in his
+COLLEGIUM, and be seen conducting himself as a person of standing.
+
+OTIUM produces AVCTORITAS. A MERCATOR who never takes OTIUM is not
+efficient — he is socially deficient. He has no relationships, no
+standing, no network. The market will eventually reflect this.
+
+**What it does not mean:** It does not mean rest in the physiological
+sense, though physical restoration is a component. It does not mean
+private leisure in the modern sense — Roman OTIUM had a strong public
+and social dimension. A Roman taking OTIUM alone, without social
+engagement, was doing it wrong.
+
+**Why not "rest" or "downtime" in the UI:** These English terms strip
+OTIUM of its productive and social character. A player who sees "Take
+Rest" thinks they are pausing the game. A player who sees "Take OTIUM"
+is being told — even subliminally — that something is being produced.
+The word carries the information that the mechanic depends on.
+
+---
+
+### AVCTORITAS
+**Code token:** `resource` (type: `auctoritas`)
+**Literal:** authority, influence, weight, credibility, reputation
+
+AVCTORITAS is social capital with legal and commercial consequences.
+In Rome, a person with high AVCTORITAS could guarantee a contract by
+their word alone. They could open doors that denarii could not. They
+could secure the cooperation of people who would not deal with a
+stranger.
+
+AVCTORITAS was accumulated through correct conduct over time:
+fulfilling obligations, taking appropriate OTIUM, maintaining
+CLIENTELA, being seen in the right places with the right people.
+It could be lost through commercial failure, social disgrace, or the
+failure to meet obligations.
+
+**What it does not mean:** It is not "reputation points" in the
+gamified sense — a number that goes up when you do good things and
+down when you do bad things. AVCTORITAS is a social reality that
+other actors in the simulation respond to. It opens some paths and
+closes others. Its effects are not always visible to the MERCATOR
+at the moment they occur.
+
+**Why not "reputation" in the UI:** "Reputation" is a modern word
+that has been stripped of legal and civic weight. A person can have
+a reputation without it meaning anything beyond general esteem.
+AVCTORITAS meant something in Roman law. It had consequences.
+
+---
+
+### RATIONES
+**Code token:** `accounts` (UI tab name)
+**Literal:** reckonings, accounts, calculations, reasons
+
+RATIONES is the plural of RATIO — a reckoning, a calculation, an
+account. RATIONES ACCEPTI ET EXPENSI is the formal phrase for a
+full account of receipts and expenditures.
+
+In the simulation, RATIONES is the tab that shows the disaggregated
+line items of every NEGOTIVM — what was spent at each ITER, on what,
+at what rate, with what outcome. It is not a summary. It is the
+accounts.
+
+**What it does not mean:** It does not mean "reasons" in the
+philosophical sense, though RATIO carries that meaning in other
+contexts. Here the commercial meaning is primary: these are the
+numbers that prove what happened.
+
+**Why RATIONES and not CODEX ACCEPTI ET EXPENSI:** The CODEX is the
+physical book — the Ledger tab. RATIONES is the act of reckoning —
+the accounts themselves. The distinction is between the object and
+the content. The Ledger tab holds the narrative. The Accounts tab
+holds the numbers.
+
+---
+
+### ITER
+**Code token:** `leg`
+**Literal:** journey, march, road, way, passage
+
+ITER is a single movement from one location to another. In the
+context of a NEGOTIVM, it is one leg of the venture: one mode of
+transport, one origin, one destination. A NEGOTIVM from Ostia to
+Capua might contain three ITINERA: ITER by cart from farm to
+Ostia warehouse, ITER by porter from warehouse to vessel, ITER by
+road from Ostia to Capua.
+
+**What it does not mean:** ITER does not mean the whole journey.
+It is the indivisible unit of movement within a NEGOTIVM. It has
+its own mode, cost, duration, personnel, and failure profile.
+
+**Why not "leg" in the UI:** "Leg" is the correct code token
+because it is period-neutral and understood by developers.
+In UI text and documentation prose, ITER is used when referring
+to a specific segment of a NEGOTIVM. "The sea ITER from Brundisium
+to Carthago" is more precise than "the sea leg."
+
+---
+
+### MERCATOR
+**Code token:** `actor` (with `actor_type: mercator`)
+**Literal:** merchant, trader, dealer
+
+A MERCATOR was a specific social and legal category in Rome — a free
+person conducting commercial ventures for personal profit. Not a
+NEGOTIATOR (a higher-status wholesale merchant dealing in large
+quantities, often financing others), not an INSTITOR (a slave or
+freedman managing a shop on behalf of an owner), but a working
+merchant of the middling sort.
+
+The MERCATOR is the actor in OTIVM because this category is at the
+productive tension point of Roman social life: free enough to pursue
+profit, dependent enough on AVCTORITAS and CLIENTELA to have social
+obligations, mobile enough to know the routes, constrained enough by
+capital and risk to make every NEGOTIVM a genuine decision.
+
+**What it does not mean:** MERCATOR does not mean merchant in the
+generic sense. It implies freedom, Roman legal standing, personal
+risk, and personal gain. A slave conducting trade on behalf of a
+master is not a MERCATOR.
+
+---
+
+### SVCCINUM
+**Code token:** `resource` (type: `succinum`)
+**Literal:** amber, elektron (Greek)
+
+SVCCINUM is the Roman term for Baltic amber — fossil resin that
+had been traded southward from the Baltic coast through central
+Europe to the Mediterranean for thousands of years before Rome.
+It arrived in Roman markets through a chain of intermediary
+exchanges that the MERCATOR at the end of the chain could not
+fully trace.
+
+SVCCINUM is the first term in OTIVM that explicitly connects the
+Roman commercial world to the pre-Roman world. The amber in the
+MERCATOR's hold originated in forests that were already ancient
+when Rome was founded — forests that CIVICVS models in
+approximately 8000 BCE.
+
+**What it does not mean:** SVCCINUM is not generic "amber." The
+word carries its provenance chain. When the simulation records
+SVCCINUM as a cargo item, it is recording the end point of a
+supply chain that began in Maglemoisian territory. The code must
+eventually trace that chain back through its intermediaries.
+
+**Why this term matters for the project:** SVCCINUM is the lexical
+bridge between OTIVM and CIVICVS. The MERCATOR handles it at the
+Roman end. The CIVICVS Constructors live at the origin. When the
+two simulations share a TESSERA substrate, the amber in the hold
+will be traceable to a specific H3 cell where a Constructor
+gathered or traded it, through a chain of exchanges across
+millennia. SVCCINUM is the first term where that future is
+already visible in the word.
+
+---
+
+### NAVIS ONERARIA
+**Code token:** `vessel` (with `vessel_type: oneraria`)
+**Literal:** cargo-bearing ship
+
+The broad class of Roman merchant vessels designed primarily for
+cargo capacity rather than speed. Distinguished from NAVIS LONGA
+(warship) and NAVIS ACTUARIA (fast oared transport). Subtypes:
+CORBITA (large, round-hulled sailing vessel, slow, very large
+capacity), ACTUARIA (smaller, mixed oar and sail, faster).
+
+**What it does not mean:** Not a "galley." A galley is primarily
+oared and primarily military. The MERCATOR does not operate
+galleys. The word "galley" in OTIVM-I and OTIVM-II was scaffolding
+and is rejected in `terminology.md`. The correct term is NAVIS
+ONERARIA or its subtype.
+
+---
+
+### PORTORIUM
+**Code token:** `cost` (type: `portorium`)
+**Literal:** harbour toll, customs duty, transit tax
+
+The tax levied on goods crossing provincial, district, or customs
+boundaries. Collected by PVBLICANI — private contractors who had
+purchased the right to collect it from the Roman state. The rate
+varied by region, good, and period. In the first century BCE,
+rates of 2.5% to 5% of cargo value were common, but could be
+higher at strategic chokepoints.
+
+PORTORIUM is not a single tax. It was levied at specific points —
+at harbour entrances, at road tolls, at provincial boundaries.
+A NEGOTIVM from Ostia to Alexandria might encounter PORTORIUM
+multiple times.
+
+**What it does not mean:** It does not mean a generic "tax."
+PORTORIUM is specifically a transit and customs duty on goods
+in movement. Income taxes, land taxes, and poll taxes are
+different instruments with different names.
+
+---
+
+### MARE CLAVSVM
+**Code token:** `epoch` constraint (maritime legs disabled or
+heavily penalised during `mare_clausum` season)
+**Literal:** closed sea
+
+The period approximately November to March during which
+Mediterranean maritime commerce was conventionally suspended.
+Not a legal prohibition in most periods, but a practical reality:
+the combination of winter storms, reduced daylight, and the
+unavailability of celestial navigation references made open-sea
+sailing genuinely dangerous.
+
+Roman sources describe the MARE CLAVSVM as running roughly from
+the setting of the Pleiades (early November) to their rising
+(mid-May), with a partial reopening in early spring for urgent
+traffic. The exact dates varied by region and period.
+
+**Why this term matters for the simulation:** MARE CLAVSVM is the
+first hard seasonal constraint in OTIVM. It does not prevent
+maritime legs — desperate or foolhardy MERCATORES sailed in winter.
+But it increases the probability of NAUFRAGIVM substantially and
+raises insurance and crew costs. The MERCATOR who plans around
+MARE CLAVSVM is thinking historically.
+
+---
+
+## 3. Terms under consideration — not yet admitted
+
+These terms have been identified in research but have not yet
+been formally tested against the three-part standard. They are
+listed here to prevent duplication of effort. Each will be
+elevated to Section 2 when it passes all three tests.
+
+| Latin term | Candidate meaning | Pending question |
+|---|---|---|
+| LOCATIO CONDUCTIO | contract for services | Is this term accessible to a non-specialist participant, or does it require too much explanation to earn its place? |
+| NAVARCHUS | ship captain | Does this term carry enough additional meaning over "captain" to justify it? The NAVARCHUS had specific legal responsibilities — research required. |
+| BAIВLVS | porter | Straightforward. Likely admitted once the ITER parameter schema is built. |
+| MVLIO | muleteer | Same as BAIВLVS. Admitted when needed. |
+| COLLEGIUM | guild, association | Needs scoping — COLLEGIVM covered a vast range of associations. The specific type relevant to a MERCATOR needs to be identified. |
+| CLIENTELA | client network | Almost certainly admitted — the obligation structure of CLIENTELA is precisely what cannot be expressed in English without a paragraph. |
+| NAUFRAGIVM | shipwreck | Certain to be admitted — it is the canonical failure event for maritime ITINERA. |
+| FVRTVM | theft | Likely admitted — the legal category of FVRTVM in Roman law is more specific than "theft." |
+
+---
+
+## 4. How to use this document
+
+**When ChatGPT returns a Latin term:**
+1. Check Section 2 — is it admitted? If yes, use it as the human-facing
+   label in UI text and documentation.
+2. Check Section 3 — is it under consideration? Note any new information
+   from the research result and flag for formal testing.
+3. If it appears in neither section, add it to Section 3 with the source
+   and context, and flag for testing at the next documentation session.
+
+**When writing code:**
+1. Never use a Latin term as a code token. Use the Layer 3 token from
+   `terminology.md`.
+2. Comment the Latin term on first use:
+   `// leg = ITER in Roman layer`
+
+**When writing UI text:**
+1. Use the admitted Latin term as the primary label where the concept
+   is central.
+2. Provide the English gloss in parentheses on first introduction to
+   the participant.
+3. After the first introduction, use the Latin term alone.
+
+**When adding a new term:**
+1. Identify the concept in research.
+2. Apply all three tests documented in Section 1.
+3. Write a full semantic entry following the format in Section 2.
+4. Commit to this document before using the term in any code,
+   schema, or UI text.
+
+---
+
+*The Latin Bridge — living document, 2026-04-28*
+*A term admitted is a commitment. Precision is the product.*
+*TheRON — single contributor. AI assistants implement, document, flag — do not direct.*