Sitemap discovery: inspect sampled URL responses

Discovery tries /sitemap.xml and /sitemap_index.xml and reads at most three child files for an index. Loc strings provide candidates. Up to eight discovered URL status checks distinguish 200, 404/410, redirect and unknown. Homepage-link patterns are compared with the discovered set.

This is not complete XML/schema validation, full-site crawling or an indexability inventory. Discovery can be incomplete or unavailable. Linked URLs may deliberately be nonindexable, duplicated or absent from a sitemap. A 200 does not verify content or indexing.

Review exact checked URLs and the intended canonical/indexable set before adding or removing entries. Treat 403, 429, 5xx and transport failures as unknown, not missing pages. Use logs and an independent inventory when completeness matters.

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url><loc>https://example.com/reference</loc></url>
</urlset>

The loc contributes a candidate to bounded discovery. It does not show that this is the only indexable page or that any crawler indexed it.

Public measurement separates Confirmed issue, Advisory, Unknown, Not applicable and Observed pass. An observed pass applies only to an explicit bounded rule; absence of an emitted failure is not a pass. Missing prerequisites do not earn repair credit.

Start 100; no discovered page URLs returns 0 (legacy unknown/coverage behavior). Subtract min(40, 12 × 404/410 count), min(40, 12 × unknown-status count), and min(15, 5 × redirect count). Homepage set differences do not deduct. These legacy unknown deductions are not evidence of defects.

Legacy values are clamped to 0..100 and rounded. They are not readiness certification, risk indicators or predicted citation outcomes. Method changes do not rewrite historical records.

The observations above describe the local implementation, not guarantees from these sources. Protocol and provider documents help interpret purpose and perform checks this audit does not implement.

• Sitemaps protocol