Methodology

What counts as a source

Only a publisher speaking about its own rules. An import requirement is only ever taken from the authority that imposes it; an airline’s policy only from that airline. A restatement on another site — however accurate it looks — is never a source here, because a restatement cannot be monitored for change and cannot be held to its own wording.

Sources are ranked by what they can settle:

• Government and border authority — authoritative for its own jurisdiction’s rules.
• Standards body — authoritative for its own standard, which applies only where an authority or a carrier requires it.
• Carrier — authoritative for its own acceptance policy, never for a government rule.

Competitor and commercial-provider material is used only to understand how the market describes things. It never becomes evidence for a requirement.

Every registered source records its canonical locator, its monitoring method and owner, and the trigger that forces a re-read. Registering a source is not the same as verifying it, and the source register shows which state each one is in.

What counts as a claim

One atomic proposition, read directly from the source, recorded with:

• the exact locator and a short extract;
• its jurisdiction and its governing layer;
• what it applies to — species, movement type, route;
• an effective interval where the source states one;
• an evidence status, a verification date, a review-due date and who verified it.

Claims are kept atomic so that one source change rewrites one claim, not a paragraph of unrelated requirements. A claim whose review date has passed is stale, and stale is a visible state, not a silent one.

How rules are built

Rules are encoded from verified claims into deterministic conditions. They evaluate to five possible outcomes — pass, fail, conditional, insufficient information, or external confirmation required — inside a scope envelope that refuses anything the rules were not built for. Missing facts never resolve in the traveller’s favour, and derived dates carry a full trace of the arithmetic that produced them.

No rule is used by any product until its bundle passes validation and its test cases pass, including tests for boundary dates and both day-counting conventions.

What has to be true before a page publishes

A page enters the public site only when its prose is finished, its meta description exists, and — for any page that answers a consequential factual question — every claim and source it cites resolves in the registers and it carries a verification date. Anything short of that keeps the page out of the production build, out of the sitemap, and out of structured data.

Two consequences worth stating plainly. A page that cites something not in the register fails the build rather than publishing. And a page’s freshness is inherited from its oldest claim, not its newest, so a single stale dependency ages the whole answer.

What this method cannot fix

It cannot detect a source that is wrong, silently updated without changing its published date, or ambiguous in a way that only matters for an unusual case. It cannot encode a rule that depends on an official’s discretion. And it cannot know your animal: fitness to travel is a veterinary judgement that no rule engine should make.