descriptionFormat property

Format to use for describing the data series group to assistive technology - including screen readers.

The series context and its subproperties are available under the variable {series}, for example {series.name} for the series name, and {series.points.length} for the number of data points.

The chart context and its subproperties are available under the variable {chart}, for example {chart.series.length} for the number of series in the chart.

{seriesDescription} refers to the automatic description of the series type and number of points added by Highcharts by default. {authorDescription} refers to the description added in series.description if one is present. {axisDescription} refers to the description added if the chart has multiple X or Y axes.

Note that if series.descriptionFormatter is declared it will take precedence, and this option will be overridden.

API Docs: https://api.highcharts.com/highcharts/accessibility.series.descriptionFormat