The cue property is a shorthand for setting cue-before and cue-after. If two values are given, the first value is cue-before and the second is cue-after. If only one value is given, it applies to both properties.
Example
For example, the following two rules are equivalent −
<style> <!-- h1 {cue-before: url("pop.au"); cue-after: url("pop.au") } h1 {cue: url("pop.au") } --> </style>