The National Jack is a square flag which indicates the nationality of all war ships which receive the prefix NRP (Navio da República Portuguesa/ Republic of Portugal's Ship) before the name. Gules, with the National Arms. Bordure in Vert, bearing a width of 1/8 of the total length of the Jack.
When sailing fully armed and commanded by an officer, the Navy's ships display two badges, the National colours and the commissioning pennant. The commissioning pennant is a ribbon made of a fabric Gules-Vert of equal length. When moored or anchored, ships hoist the national jack to the bow. Both the national colours and the jack are hoisted at 8 o'clock and lowered at sunset.
