Callout

aside, .slate-callout. Not operable, so this component has no keyboard interaction to document: it is a set-off box, reached the same way any other content is.

The element

The warn tone

The label is what makes the tone accessible: a warn callout differs from a plain one by the colour of a 2px bar and by nothing else, so in greyscale, under a forced-colours palette, or to a reader with a colour vision deficiency the two are one box. The word carries the distinction WCAG 1.4.1 requires; Slate ships the styling, only the author ships the word.