List myList = new List(); // add items to the list myList.ListItems.Add(new ListItem(new Paragraph(new Run("Item 1")))); myList.ListItems.Add(new ListItem(new Paragraph(new Run("Item 2")))); myList.ListItems.Add(new ListItem(new Paragraph(new Run("Item 3")))); // insert a new item at index 1 myList.ListItems.Insert(1, new ListItem(new Paragraph(new Run("New Item"))));In this example, a new List is created and three items are added to it using the Add method. The Insert method is then used to add a new item at index 1 (position 2). The package library for this namespace is likely to be part of the .NET Framework.