# Product compatibility data: prove the exact accessory match

> Separate compatible products from related products. Use exact model pairs, revisions, adapters, and source evidence, with a downloadable decision ledger.

By George Kelly · Published 2026-09-20 · Updated 2026-09-20

Publication: iamgeorgekelly (https://www.iamgeorgekelly.com)

Canonical: https://www.iamgeorgekelly.com/field-guide/product-compatibility-evidence

## Short answer

A related product, matching dimension, or similar model name does not prove compatibility. Identify the exact accessory and target, check an authoritative statement for that pair and revision, and retain required conditions. Record supported, contradicted, or unknown rather than converting missing evidence into a yes or no.

## Related products are not necessarily compatible products

A shopper may ask whether a tray fits a stand or whether a replacement part works with an older model. The task is a relationship between two exact products. A category recommendation or a family-level match leaves that relationship unresolved.

Schema.org offers isAccessoryOrSparePartFor for an accessory or spare-part relationship. Its isRelatedTo property expresses a broader relationship. These names describe data; they do not perform a fit test or establish whether the underlying assertion is true. The evidence method below is an editorial proposal, not a Schema.org requirement.

Sources: [Schema.org: isAccessoryOrSparePartFor](https://schema.org/isAccessoryOrSparePartFor); [Schema.org: isRelatedTo](https://schema.org/isRelatedTo)

## Write the pair before reviewing the claim

Capture the accessory identifier, target identifier, target revision, region where relevant, and any required adapter. Retain the source revision and exact location of the compatibility statement. A screenshot or document link without the applicable model details is difficult to reuse reliably.

A useful evidence record names the manufacturer table, specification, or other approved authority for that relationship. Preserve exclusions as well as inclusions. If two sources disagree, send the conflict to the accountable owner instead of selecting whichever statement permits the purchase.

| Question | Evidence to retain |
| --- | --- |
| Which two things are being matched? | Exact accessory and target IDs, including revision or generation. |
| Under what conditions? | Required adapter, supported configuration, and relevant exclusions. |
| Who supports the claim? | Approved source, document revision, exact section or row, and review date. |
| What remains unresolved? | A named missing fact or source conflict, with the next evidence needed. |

[Download the fictional compatibility ledger and blank record (JSON)](https://www.iamgeorgekelly.com/downloads/product-compatibility-evidence.json)

## One document can produce three different decisions

Consider an invented manual stating that Tray A is specified for Stand 01 revision B without an adapter, excludes revision C, and says nothing about revision D. Those are three different evidence states, even though the model family and accessory name are the same.

The JSON ledger preserves the fictional statement and the reasoning for each pair. It is a template for review, not an automated compatibility service. Its null adapter field is accompanied by adapterRequirementKnown so that no adapter required cannot be confused with requirement unknown.

| Requested target | Decision | Reason |
| --- | --- | --- |
| Stand 01, revision B | Supported under the stated conditions | The exact revision and adapter condition are explicit. |
| Stand 01, revision C | Contradicted | The source explicitly excludes this revision. |
| Stand 01, revision D | Unknown | The source does not address this revision. |

## Do not fill the evidence gap with a plausible shortcut

Shared brand, visual similarity, matching outer dimensions, or frequent co-purchase can help locate candidate evidence. They do not settle the relationship. A revision can change a connector, interface, mounting pattern, or required part while preserving a familiar name.

Compatibility assertions should also keep direction and conditions. A statement that one accessory is intended for a target is not a license to substitute every related accessory. Do not generalize an accepted pair into an entire model family.

Next step: [Compare measurements without confusing units or packaging](https://www.iamgeorgekelly.com/field-guide/product-dimensions-unit-conversion) — Resolve the numerical comparison while preserving the separate compatibility question.

## Make the agent’s answer auditable

For a supported pair, state the exact products, applicable revision, conditions, and source location. For a contradiction, identify the specific exclusion. For an unknown, identify the missing information and the source needed to resolve it. Do not summarize all three outcomes as a generic low-confidence recommendation.

Before publishing a product relationship or recommending an accessory, inspect the current source and the selected items. This ledger does not assess physical installation, certify fit, or replace manufacturer instructions. Its job is to prevent an unsupported match from quietly becoming a catalog fact.

Next step: [Resolve the identifiers on both sides of the pair](https://www.iamgeorgekelly.com/field-guide/product-identifiers-sku-gtin-variants) — Compatibility evidence is only useful when it points to the intended items.

Next step: [Route conflicting source claims to an owner](https://www.iamgeorgekelly.com/field-guide/product-data-ownership) — A disagreement requires an authority decision, not more fluent copy.

## Sources and scope

- [Schema.org: isAccessoryOrSparePartFor](https://schema.org/isAccessoryOrSparePartFor) — Defines an accessory or spare-part relationship. It does not validate the claim; the ledger and decisions are original editorial examples. Checked 2026-09-20.

- [Schema.org: isRelatedTo](https://schema.org/isRelatedTo) — Defines broader product relatedness. It is not equivalent to an explicit compatibility relationship. Checked 2026-09-20.

## Related reading

- [SKU vs GTIN: differences, barcodes, and variant IDs](https://www.iamgeorgekelly.com/field-guide/product-identifiers-sku-gtin-variants/index.md)

- [Product dimensions vs package dimensions: compare units safely](https://www.iamgeorgekelly.com/field-guide/product-dimensions-unit-conversion/index.md)

- [Does the product page match the variant you submitted?](https://www.iamgeorgekelly.com/field-guide/product-variant-acceptance-test/index.md)

## Cite this guide

George Kelly. Product compatibility data: prove the exact accessory match iamgeorgekelly. Updated 2026-09-20. https://www.iamgeorgekelly.com/field-guide/product-compatibility-evidence

Library navigation: [Choose a task](https://www.iamgeorgekelly.com/field-guide/start-here) · [Source directory](https://www.iamgeorgekelly.com/field-guide/sources) · [Editorial policy](https://www.iamgeorgekelly.com/for-agents#editorial-policy)

## Editorial note

AI-assisted research and drafting. Provider-specific claims link to primary sources. Frameworks are editorial proposals; worked examples are illustrative and are not employer performance results.