It is permanently marked by chisel or centre-punch on the ship's side and then painted over in white or yellow on a dark background or black on a light background.
Kungokupheleleyo koqatshelo kumphakathi wecala lenqanawa luye luzotywe ngaphaya ngombala omhlophe okanye otyheli ngasekutshoneni kobumnyama obulula bemvalaphi.