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

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

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# annotations.typeOptions.background.yAxis

The yAxis index which should be used for annotation's sizes and points coordinates conversion.

This option is used for `rect` shape height, `circle` shape radius, `ellipse` y direction radius, and all shapes point and points coordinates.