# at-rule-property-required-list Specify a list of required properties for an at-rule. ```css @font-face { font-display: swap; font-family: 'foo'; } /** ↑ ↑ ↑ * At-rule and required property names */ ``` ## Options `object`: `{ "at-rule-name": ["array", "of", "properties"] }` Given: ``` { "font-face": ["font-display", "font-family", "font-style"] } ``` The following patterns are considered violations: ```css @font-face { font-family: 'foo'; src: url('./fonts/foo.woff2') format('woff2'); } ``` ```css @font-face { font-family: 'foo'; font-style: normal; src: url('./fonts/foo.woff2') format('woff2'); } ``` The following patterns are _not_ considered violations: ```css @font-face { font-display: swap; font-family: 'foo'; font-style: normal; src: url('./fonts/foo.woff2') format('woff2'); } ```