# 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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# xAxis.plotLines.label.formatter

Callback JavaScript function to format the label. Useful properties like the value of plot line or the range of plot band (`from` & `to` properties) can be found in `this.options` object. 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`.