Structured data
Structured data is machine-readable markup, usually JSON-LD, that states what a page is about in a defined vocabulary rather than leaving it to be inferred from the prose.
Two rules decide whether it helps or hurts. It has to match the visible page, because markup describing content the page does not contain is a manual action risk rather than a technicality. And an entity should be defined once and referenced by @id everywhere else, because a validator that does not resolve the reference will propose completing it, which writes a second conflicting definition and breaks the graph it was trying to fix.
Required properties are the ones that gate a rich result. A validator that reports every optional property as a warning trains people to ignore it.
Related
Entity
An entity is a thing a search or answer engine can identify and hold facts about, such as a company, a person, a product or a place, as distinct from the words used to describe it.
Answer engine optimisation (AEO)
Answer engine optimisation is the practice of structuring a site so that AI assistants such as ChatGPT, Claude, Perplexity and Google's AI Overviews name and cite it when answering a question, rather than optimising for a position in a list of links.
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