Structured data
Also known as Schema markup
Machine-readable markup that labels what content is, helping engines extract and trust it.
Structured data, usually schema.org markup in JSON-LD, tells a machine that a block of text is an FAQ, a product, an article, or an organization. That makes your content easier to parse and quote.
It does not guarantee a citation, but it removes ambiguity. When an engine can cleanly extract a fact, it is likelier to use it.