Chapter 0.3 — Glossary

chapter: 00-introduction/03-glossary
version: 1.0.0
status: stable
last_reviewed: 2026-05-26
owners: [docs]

This glossary is the canonical source of meaning. When a term appears in bold in any other chapter, it is defined here.

A

• ACM (Agency Credit Memo) — A post-issuance credit issued by an airline to an agency, reversing or reducing a prior ADM or correcting an overcharge.
• ADM (Agency Debit Memo) — A post-issuance debit issued by an airline to an agency for fare misuse, missed taxes, incorrect class of service, etc. Drives a payable that must be researched, possibly disputed, and ultimately settled.
• AP (Accounts Payable) — Money the partner owes to suppliers. travoBooks tracks this per supplier with ageing.
• AR (Accounts Receivable) — Money the partner is owed by customers. Tracked per customer with ageing.
• Audit log — An append-only record of every state-changing event in the platform, keyed by actor_id, entity_type, entity_id, before, after, timestamp.

B

• BSP (Billing and Settlement Plan) — IATA's centralised airline-agency settlement mechanism. Agencies report sales; the BSP consolidates, deducts commission, and produces a net settlement file.
• BSP report — The periodic file (typically weekly or fortnightly per market) telling the agency what it owes IATA on behalf of airlines.
• Booking — The travoBooks internal record representing a customer's intent to travel. May contain one or more segments and may span multiple suppliers. Identified by BKG-{partner}-{seq}.
• Booking class — The fare bucket / RBD (reservation booking designator) on a flight segment.

C

• CoA (Chart of Accounts) — The hierarchical list of account codes used to classify journal entries.
• Commission — Compensation paid by a supplier to the agency for selling its inventory. May be a percentage of base fare, a flat amount, or a tiered/override structure.
• Cost centre — A reporting dimension below the partner level, used for departmental P&L (e.g. "Corporate Desk", "Leisure Desk").
• CSRF — Cross-Site Request Forgery; defended against on every cookie-auth write.
• Customer — The entity to whom an invoice is issued. May be a B2B sub-agent, a corporate account, or an individual.

D

• DAC — IATA code for Dhaka, Bangladesh. Used as the home-base reference in many examples.
• Deferred revenue — Revenue received in cash but not yet earned because the service (travel) has not yet been rendered. Sits on the balance sheet as a liability until service date.
• DOM — Domestic.

E

• EMD (Electronic Miscellaneous Document) — A non-flight document issued through an airline (ancillaries, residual value, etc.). Has its own document number, separate from a ticket.

F

• Fare basis — The alphanumeric code identifying the fare rule applied to a ticket (e.g. YEX1MBD).
• FX (Foreign Exchange) — Currency conversion. travoBooks stores FX rates with their effective timestamp and source.
• Functional currency — The currency a partner produces statutory financial statements in.

G

• GAAP — Generally Accepted Accounting Principles. The US variant is referred to as US-GAAP.
• GDS (Global Distribution System) — Centralised supplier inventory and booking system. The three majors are Amadeus, Sabre, and Travelport.
• GL (General Ledger) — The complete record of all financial transactions. Built from posted journal entries.
• GST — Goods and Services Tax. Applies in India, Australia, Canada, Singapore, and elsewhere.

I

• IATA — International Air Transport Association.
• Idempotency key — A client-generated unique key sent with a POST/PUT to ensure that retrying the request does not cause a duplicate effect.
• IFRS — International Financial Reporting Standards.
• INT — International.
• Invoice — The bill issued to a customer. Has lifecycle states: draft → issued → paid → closed (with void as an exit).
• Issue date — The date a ticket or invoice was created. Distinct from service date.

J

• Journal entry — The atomic unit of accounting. A balanced set of debits and credits (sum to zero) plus metadata. Identified by JE-{partner}-{seq}.

L

• LCC (Low-Cost Carrier) — Airlines outside the GDS that are typically integrated via direct APIs and settled outside the BSP.
• Ledger — See General Ledger.

M

• Markup — Amount added by the agency on top of supplier cost.
• Mid-office — The function and software that sits between front-office booking and back-office accounting; in travoBooks, integrated.

N

• NDC (New Distribution Capability) — IATA's XML-based standard for richer airline content distribution. travoBooks supports NDC alongside classic GDS.
• Net rate — Supplier rate without commission visible; the agency adds markup to derive a sell price.

P

• Partner — A tenant. The legal entity whose data is isolated by partner_id.
• PAT (Personal Access Token) — A long-lived API token tied to a specific user.
• Payment — A record of money moving in (receipt from customer) or out (settlement to supplier or refund to customer).
• PNR (Passenger Name Record) — The supplier-side booking reference. Six characters for GDS PNRs; varies for direct.
• Posting — The act of writing a journal entry to the general ledger. Once posted, a JE is immutable.

R

• RBAC (Role-Based Access Control) — Permissions are granted to roles; users are assigned roles.
• Reconciliation — Matching internal records to external statements (bank, BSP, payment processor).
• Refund — Reversal of all or part of a previously-issued ticket or invoice. Generates a reversing journal entry.
• Reissue — A change to a ticket that may add or refund fare difference.
• Reporting currency — The currency in which a particular report is rendered. May differ from functional currency.
• Revenue recognition — Moving an amount from deferred revenue to recognised revenue on the income statement, typically at service date.

S

• Service date — The date the customer actually consumes the service (i.e., the flight date or check-in date). Drives revenue recognition timing.
• Supplier — The party from whom the agency procures inventory. Airlines, hotels, bedbanks, car rental, insurance providers, etc.
• Subscription — The billing relationship between travoBooks and a partner for use of the platform.

T

• Tenant — Synonymous with partner in the multi-tenancy chapter.
• Ticket — The document issued by an airline (via the agency) entitling carriage. Identified by the airline's 13-digit ticket number.
• Transaction currency — The currency in which a specific event occurred.
• TST (Transitional Stored Ticket) — A pricing record on a PNR before issuance.

V

• VAT — Value Added Tax. The European variant of GST.
• Void — Cancellation of a ticket within the airline's void window (typically end of issuance day). Unlike a refund, a void may not pass through BSP at all.

W

• Webhook — An HTTPS callback fired to a partner-configured URL when an event of interest occurs. Signed with HMAC.

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Next: 04-tech-stack.md — implementation technologies and dependency baseline.