Concisely defined technical terms with primary specification links (W3C, IETF RFC, Schema.org, BFSG/EAA) covering website diagnostics, AI search visibility, and accessibility pre-checks.
German federal law implementing the European Accessibility Act (EAA), applicable since June 28, 2025 to online shops and consumer e-commerce services. Micro-enterprises providing services (fewer than 10 employees and up to €2M turnover) are exempt.
Primary Specification: https://www.gesetze-im-internet.de/bfsg/
Internationally recognized W3C Web Content Accessibility Guidelines. Level AA forms the technical foundation of the European standard EN 301 549 V3.2.1 for websites and mobile applications.
Primary Specification: https://www.w3.org/TR/WCAG21/
European standard specifying accessibility requirements for ICT products and services, referencing WCAG 2.1 Level AA criteria for web content.
Primary Specification: https://www.etsi.org/deliver/etsi_en/301500_301599/301549/
Practices for structuring website content and entity data to improve the chances of retrieval, mention, and source citation in generative AI answer systems.
Primary Specification: https://arxiv.org/abs/2311.09735
Open community proposal (llmstxt.org) for a Markdown file at /llms.txt providing AI agents and developer tools with a concise index of key pages.
Primary Specification: https://llmstxt.org/
Root text file standardized in RFC 9309 (Robots Exclusion Protocol) that controls which search and AI crawlers may access specific paths on a domain.
Primary Specification: https://www.rfc-editor.org/rfc/rfc9309.html
Directive via HTML meta tag or HTTP X-Robots-Tag header instructing search engines not to index a page.
Primary Specification: https://developers.google.com/search/docs/crawling-indexing/block-indexing
HTML link element (<link rel="canonical">) indicating the preferred canonical URL among duplicate or parameterized URLs (RFC 6596).
Primary Specification: https://www.rfc-editor.org/rfc/rfc6596.html
HTML link or XML sitemap annotation mapping language and regional variants of a page (e.g., de, en, x-default).
Primary Specification: https://developers.google.com/search/docs/specialty/international/localized-versions
Collaborative community vocabulary founded by Google, Microsoft, Yahoo, and Yandex for structured data markup on the web.
Primary Specification: https://schema.org/
W3C specification for embedding Linked Data in JSON format inside HTML documents via <script type="application/ld+json">.
Primary Specification: https://www.w3.org/TR/json-ld11/
OpenAI web crawler used for ChatGPT Search to link and cite websites in search results, controlled separately from the GPTBot training crawler.
Primary Specification: https://platform.openai.com/docs/bots
OpenAI crawler used to collect public web content for training generative AI models.
Primary Specification: https://platform.openai.com/docs/bots
Web crawler operated by Perplexity AI to index web pages for answer synthesis with source citations.
Primary Specification: https://docs.perplexity.ai/guides/bots
Web crawler operated by Anthropic to fetch public web content for Claude AI systems.
Primary Specification: https://support.anthropic.com/
robots.txt control token allowing publishers to manage whether their content is used for Google Gemini training and Vertex AI grounding without affecting Google Search indexing.
Primary Specification: https://developers.google.com/search/docs/crawling-indexing/overview-google-crawlers
Applebot crawls content for Siri and Spotlight search, while Applebot-Extended controls usage for Apple Intelligence foundation model training.
Primary Specification: https://support.apple.com/en-us/119829
HTTP security header standardized in RFC 6797 instructing browsers to interact with a domain exclusively over HTTPS.
Primary Specification: https://www.rfc-editor.org/rfc/rfc6797.html
HTTP response header standard defining approved sources for scripts, styles, fonts, and images to mitigate XSS and unauthorized external requests.
Primary Specification: https://www.w3.org/TR/CSP3/
WCAG 2.1 Level AA success criterion requiring a minimum contrast ratio of 4.5:1 for normal text (3:1 for large text) against its background.
Primary Specification: https://www.w3.org/WAI/WCAG21/Understanding/contrast-minimum.html
WCAG 2.1 criterion requiring text alternatives (alt attributes) for non-text content so screen readers can convey meaning to users.
Primary Specification: https://www.w3.org/WAI/WCAG21/Understanding/non-text-content.html
Accessibility requirement that every form input has a programmatically associated label (<label for="..."> or aria-label).
Primary Specification: https://www.w3.org/WAI/WCAG21/Understanding/info-and-relationships.html
Machine-readable XML file listing canonical indexable URLs of a website in accordance with the sitemaps.org protocol.
Primary Specification: https://www.sitemaps.org/protocol.html
Security mechanism ensuring web scanners validate DNS resolution and block requests to private, loopback, or link-local IP ranges.
Primary Specification: https://owasp.org/Top10/A10_2021-Server-Side_Request_Forgery_%28SSRF%29/
Joint public authority of the German federal states based in Magdeburg responsible for market surveillance under the BFSG.
Primary Specification: https://ms.sachsen-anhalt.de/themen/menschen-mit-behinderungen/aktuelles/marktueberwachungsstelle-der-laender-fuer-die-barrierefreiheit-von-produkten-und-dienstleistungen