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Of course it's possible to render multi-line categories. In order to do so, you should define it in yAxis.categories
array with HTML markup and link your data to desired category by setting y
value of a task. By default, HTML markup is parsed and rendered as SVG text, but if you want to achieve more advanced output, you can enable it in yAxis.labels.useHTML
https://www.highcharts.com/docs/chart-c ... formatting
Let me know if that was what you were looking for.