SEO letter X

  • What is an XML sitemap?

    An XML sitemap lists a site’s URLs for search engines to discover. Keep it up to date and submit it to Google Search Console to improve crawl coverage. Are you...

    Read More
  • What is the X-Robots-Tag?

    The X-Robots-Tag is an HTTP header that controls indexing and serving of non-HTML files (like PDFs). Use it to apply noindex or nofollow at the server level when needed. Have...

    Read More
  • What is X-Content-Type-Options?

    HTTP header: nosniff. Security best practice. Prevents browsers from MIME-sniffing incorrectly. Protects SEO assets like JS/CSS from being misinterpreted. Are you worried about sneaky security threats that can hijack your...

    Read More
  • What is X-Frame-Options (SEO & Security)?

    HTTP response header that prevents clickjacking by controlling iframe embedding. SEO impact: Can block embedding of your pages → reduces link equity via embeds. Are you worried about a sneaky...

    Read More
  • What is X-Robots-HTTP Directives for Googlebot?

    Extends robots.txt directives to individual file-level instructions via headers. Useful for media SEO (images, videos, PDFs). Are you struggling to keep some of your private or low-value pages out of...

    Read More
  • What is X-Robots-Tag?

    HTTP header version of meta robots. Allows controlling indexation for non-HTML files (PDFs, images, video). Example: X-Robots-Tag: noindex, nofollow Are you struggling to keep some of your private or low-value...

    Read More
  • What is X-Search Logs (Experimentation in IR)?

    “X-Logs” shorthand in academic IR papers for experimental search logs. Used in query modeling, click-through studies. Do you ever wonder what Google really learns every time someone uses the search...

    Read More
  • What is X-UA-Compatible?

    Legacy IE header for rendering mode. SEO tie-in: Improper use could break rendering for crawlers if fallback HTML fails. Are you worried that some of your website visitors might see...

    Read More
  • What is X.509 Certificates (HTTPS SEO)?

    SSL/TLS certificates based on X.509 standard. Core to HTTPS (ranking signal, trust, crawl integrity). Are you seeing a scary “Not Secure” warning in the browser when people visit your website?...

    Read More
  • What is XAI (Explainable AI in SEO/IR)?

    Explainable AI techniques (e.g., SHAP, LIME) applied to ranking models. Useful for SEO research to understand why Google ranks a page higher/lower. Do you sometimes feel like Google’s ranking decisions...

    Read More
  • What is Xapian (Open-Source IR Engine)?

    A probabilistic IR library used in research/enterprise retrieval. Relevant for SEO pros exploring IR fundamentals beyond Lucene/Elastic. Are you frustrated when the search bar on your own website gives terrible...

    Read More
  • What is Xenocode / Obfuscated JS & SEO?

    Some sites use obfuscation for JS (sometimes called “xenocode”). SEO issue: If Googlebot fails to render obfuscated JS, content may be missing from index. Are you worried about sneaky hackers...

    Read More
  • What is XenonRank (Academic IR Algorithm)?

    A rare ranking function from academic literature. Explores weighted term distributions + document priors. Do you sometimes wonder what makes one piece of content better than another in the eyes...

    Read More
  • What is XGBoost in Learning-to-Rank?

    Gradient boosting framework widely used in search ranking competitions & SEO tools. Example: LambdaMART + XGBoost still baseline for some search systems. Do you wish you knew exactly how a...

    Read More
  • What is XHTML (Extensible HTML)?

    Strict XML-based version of HTML. SEO tie-in: Some older sites still serve XHTML → must check for crawl/indexing issues if served with wrong MIME type. Are you worried that the...

    Read More
  • What is XLink (XML Linking Language)?

    Used in XML documents for defining hyperlinks. Rare but relevant in sitemaps & structured data formats. Do you worry about making your internal links super clear for search engines and...

    Read More
  • What is XML Sitemap?

    File (sitemap.xml) that lists URLs for crawling. Critical for large sites, new content discovery, canonical hints, and crawl efficiency. Supports priority, frequency, lastmod. Are you worried that Google might be...

    Read More
  • What is XML-RPC & SEO Risks?

    Remote procedure call protocol in XML. On WordPress, can be abused in spam attacks → indirect SEO risks (server overload, crawlability). Are you worried about sneaky hackers slowing down your...

    Read More
  • What is XMP Metadata (Adobe / Media SEO)?

    XML-based standard for embedding metadata in PDFs, images, videos. Helps with file SEO (PDF ranking, image indexing, Google Images). Are you posting beautiful images and videos on your website only...

    Read More
  • What is XOR in Retrieval Models?

    Boolean retrieval operator (exclusive OR). Rarely used directly, but appears in legacy IR systems and query rewriting engines. Do you get confused by how some search results seem to match...

    Read More
  • What is XPath (XML Path Language)?

    Query language for navigating XML docs. SEO use: Scraping SERPs, structured data extraction, and log analysis pipelines. Do you wish you had a secret tool to help Google find the...

    Read More
  • What is XPath in technical SEO?

    XPath navigates XML/HTML document structures for scraping and analysis. Use XPath selectors in crawling tools to extract specific elements, monitor competitor changes, and automate SEO audits. Do you wish you...

    Read More
  • What is XQuery?

    More powerful than XPath for querying XML. Technical SEO → sometimes used in advanced data extraction workflows for big XML-based sitemaps. Do you worry about managing the huge amount of...

    Read More

SEO Glossary