public Object Tag { get; set; }

Public Property Tag As Object
	Get
	Set

public:
property Object^ Tag {
	Object^ get ();
	void set (Object^ value);
}

Property Value

Any type derived from the Object class can be assigned to this property. If the Tag property is set through the Windows Forms designer, only text can be assigned.

A common use for the Tag property is to store data that is closely associated with the control. For example, if you have a control that displays information about a customer, you might store a DataSet that contains the customer's order history in that control's Tag property so the data can be accessed quickly.

Reference