blockquote
<blockquote>, block quotation, cite attribute, pull quoteDefinition
The element for a quotation set off from the text as its own block — someone else’s words, with an optional cite attribute for the source URL and, by convention, a <footer> or <cite> element inside or after it naming the author — as against <q> for a quotation inside a sentence
Markdown’s > renders one, which is why every quote in this garden’s notes is one already. The semantics matter to two readers: a screen reader announces the quotation, and a search engine treats it as not this page’s own claim. The attribution is the part people get wrong — the <cite> element is for the work being quoted, not the person, so a name goes in a <footer> inside the blockquote. Not for indentation: a <blockquote> used to inset a paragraph is a lie the page tells assistive technology.
Someone else said this. The element says so, and the attribution says who; using it to indent is claiming a quote that is not there.