# 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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# navigation.bindings.verticalLabel.annotationsOptions.labelOptions.formatter

Callback JavaScript function to format the annotation's label. Note that if a `format` or `text` are defined, the format or text take precedence and the formatter is ignored. `This` refers to a point object. The callback also receives an argument `ctx` so that arrow-functions can access the same context (the point in this case) as normal functions can using `this`. Since v12.6.0, the callback receives `ctx`.