Technical reference

Definitions and checklists for labels that are often over-interpreted in audits. Protocol meaning, platform guidance, and diagnostic inference stay separate.

Library contract

Reference pages cite current primary documentation and show their review date. They clarify a result; they do not replace the source standard.

01
Reference 01 · checked 22 Aug 2026

HTTP status codes for web diagnostics

A compact diagnostic reference for common 2xx, 3xx, 4xx, and 5xx responses, with protocol meaning separated from SEO inference.

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02
Reference 02 · checked 22 Aug 2026

Crawler user agents: claim, token, and verification

A reference for classifying crawler strings without treating an easily spoofed header as verified identity.

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03
Reference 03 · checked 22 Aug 2026

Robots directives in headers and HTML

Read robots meta elements and X-Robots-Tag response headers as page-level controls, with crawler access and conflicts kept visible.

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04
Reference 04 · checked 22 Aug 2026

Crawler verification methods compared

Compare user-agent matching, published IP ranges, forward-confirmed reverse DNS, operator tools, and request-log evidence without overstating identity.

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