This toolbar button is for inserting a [parameter field](../../explorers/field/parameter-fields.md).
After selecting this menu option, move the mouse cursor to the position in the report where the parameter field should appear, and keep the mouse button pressed while adjusting its size. When the mouse is released, the [new parameter dialog](../../../parameters/create-new-parameter.md) appears.
Other options for the field can be changed via the [field properties](../../dialogs/field-properties/properties.md) dialog.