Schema Markup

Schema markup is a standardized vocabulary of tags (from Schema.org, maintained by Google, Bing, Yahoo, and Yandex) added to web page HTML to provide explicit machine-readable context about the page’s content. It describes entities on the page (articles, products, people, organizations, events, definitions, FAQs) in a format that search engines and AI systems can parse without relying on natural language inference. Properly implemented schema markup enables rich results (star ratings, FAQ dropdowns, breadcrumbs, event listings) in Google SERPs and improves the probability of being cited by AI answer engines.

How it works

Schema markup is most commonly implemented as JSON-LD (JavaScript Object Notation for Linked Data), a script block in the page’s HTML that does not affect visible content. The JSON-LD block declares the entity type (e.g., ‘@type’: ‘Article’ or ‘@type’: ‘DefinedTerm’) and populates its properties (name, description, author, datePublished, etc.) with page-specific values. Google’s Rich Results Test and Schema Markup Validator can verify that markup is syntactically valid and eligible for rich result features. WordPress SEO plugins like Rank Math and Yoast SEO automate schema generation for common post types.

Key facts

• JSON-LD preference: Google recommends JSON-LD over Microdata and RDFa because it can be injected without modifying visible HTML and is easier to maintain.
• Rich result eligibility: Schema types that unlock specific rich result features include FAQPage, HowTo, Product, Recipe, Review, Event, BreadcrumbList, and VideoObject.
• Structured data as AI signal: LLMs and AI RAG systems use schema markup to identify and extract structured information from pages, making schema increasingly important for AI visibility beyond traditional SEO.

For builders

For WikiWalls as a glossary publisher, implementing DefinedTerm schema on every entry page is the highest-priority schema investment, as it signals definitional content to both Google’s featured snippet systems and AI answer engines. Article schema on editorial posts, BreadcrumbList schema for navigation context, and Speakable schema for voice search eligibility round out the publisher schema stack. Automating schema generation through WordPress post templates or a plugin ensures consistent markup across the entire content catalog without per-post manual effort.

Sources

• Schema.org. Full type hierarchy. schema.org
• Google. Introduction to structured data. developers.google.com
• W3C. JSON-LD 1.1 recommendation. w3.org
• JSON for Linking Data. Learning resources and primer. json-ld.org
• Google. Search Central Blog with structured-data updates. developers.google.com