Inclusion rule: who is in the table and who is not
An inclusion rule is the stated test for appearing in a table. Written down, it turns a list of vendors into a population a reader can argue with. Unwritten, it lets the table quietly contain whoever the author had heard of. As of 2026-09-22.
| Decision | Consequence if unstated |
|---|---|
| What kind of product qualifies | The table mixes categories silently |
| What language of site qualifies | Selection follows the author reading |
| How a borderline case is handled | Borderlines land on taste |
| What is counted for each row | Two cells can measure different things |
Inclusion rule. The decisions an inclusion rule has to make explicit. Each is stated beside every table in this register. Order. Most consequential decision first.
1An unstated rule is a hidden editorial hand
Any table of vendors is a selection. Without a written test, the selection reflects what the author found, which correlates with marketing spend and with the language the author reads.
That is the most common and least visible bias in a comparison. Writing the rule down does not remove it, and it does make it arguable: a reader can name a vendor that passes the test and is missing.
2The rule has to cover the cells as well as the rows
Deciding who is in a table is half the job. The other half is deciding what goes in each cell, because two rows filled from different kinds of evidence are not comparable however carefully the rows were chosen.
So each table here states both: the test for being a row, and the rule for what fills a cell. The second is where the interesting decisions are, and where this register differs most from an ordinary comparison.
3What is excluded here, and why
Products without a public English site, because they could not be read under one rule. Resellers and aggregator apps, because their language support is somebody else. And anything requiring an account to see, because a reader could not repeat the check.
Each exclusion loses real products. They are stated rather than defended, so a reader who thinks the boundary is wrong knows exactly which line to argue with.
A definition, not a measurement: no vendor figure appears here that is not also in the register. Every table in this register prints its inclusion rule and its ordering beneath it.
Nearby terms: Spot check, Dialect. The whole vocabulary is at terms; nothing on this page is a claim about a named product.