Correct statement. From the NCL FAQ'S:
Wine & Champagne Policy
Guests may bring bottles of wine and champagne on board. When bottles are brought on board and served or consumed in any restaurant, public room area or in their stateroom, a corkage fee will be charged according to bottle sizes noted below.
750 ml Bottle: $15.00 USD
1,500 ml Magnum: $30.00 USD
Wine or champagne sent directly to the ship by travel agents, friends, family, etc. or from another retail source, are subject to the same fees. Box wines are not allowed on board.
Corkage Fee is not applicable to guest with beverage package.
* Norwegian encourages the responsible use of alcohol and accordingly reserves the right to permanently or temporarily revoke the drinking privileges of any guest who violates Norwegian's Guest Code of Conduct or who is deemed a danger to himself, herself or others by vessel management. Continued abuse of alcohol while sailing and/or violation of Norwegian's alcohol policy may result in immediate disembarkation.