# Welcome to the Highcharts Gantt JS (gantt) Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

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# plotOptions.series.label.formatter

Callback function to format each of the series' labels. The `this` keyword refers to the series object. By default the `formatter` is undefined and the `series.name` is rendered. Since v12.6.0, the callback also receives `ctx` as the first argument, so that arrow functions can access the same context as regular functions using `this`.