Checks at the front door are per route

The pattern readers notice

You go through whatever stands at the entrance on one route. Later you arrive on another and are asked again. Nothing you did on the first route counts on the second.

It is mildly irritating and it is exactly what should happen, for the same reason the session does not travel: the check is a transaction between you and one host.

Why a check cannot be shared

Whatever records the fact that you passed is held against the host that issued it. A different host has no such record for you and no reason to assume anything about you. It is not that the market forgot. It is that this route has not met you.

A market could in principle arrange things differently, and this site has no way of knowing what any market does. What a reader can rely on is that being asked again is unremarkable and not a signal.

The thing it must never be read as

It is not evidence that the route you have arrived on is fake, and it is not evidence that the route you left was. The presence of an entrance check tells you nothing about authenticity in either direction, because anything can put a check in front of itself.

That is worth saying because a check has an air of officialdom, and a reader in a hurry can take passing one as having verified something. It verifies nothing about the address, and the study on what a list proves makes the same argument about a different kind of reassurance.

What it does tell you

• That something is answering on this route, which is more than you knew a moment ago.
• That you are being treated as a new arrival, which is expected on a route you have not used lately.
• Nothing at all about the other two routes, which have their own state and their own entrances.

The cumulative cost of plurality here

Three routes means three entrances. A reader who rotates deliberately pays the entrance cost more often than one who does not, and that is the honest cost of the practice recommended in rotating on purpose.

It is small, it is paid at the start of a visit, and it buys the thing described in that study. But it is a real cost and it is the main reason people stop rotating.

Why this is a plurality subject at all

A single address has an entrance too, and passing it would be unremarkable. What makes this a study is repetition without progress: the same check, passed again, with the first pass having been useless.

That produces a specific misreading, which is that something has gone wrong or been lost. Naming the mechanism removes the misreading entirely.

The practical form

Expect it on any route you have not used recently, treat it as confirmation that you have changed route rather than as a problem, and do not let having passed it persuade you of anything about the address itself.

A boundary worth stating explicitly

Passing an entrance is not evidence of anything about the place you have entered. That sentence is the whole boundary, and it is worth stating because entrance checks carry an official air that readers unconsciously borrow.

The check is between you and whatever is answering. It says nothing about whose service that is, which is why the only check that matters remains the one performed on the string before you arrive at all.

What this study is not. It is not a description of what any particular check is or how it works, which varies and is not something this site examines.