British Flags: Their Early History, and Their Development at Sea / With an Account of the Origin of the Flag as a National Device

by William Gordon Perrin

O Flag divided diagonally yellow and red

U " " quarterly red and white

X " white with blue cross

Y " striped diagonally yellow and red in ten stripes

Z " divided diagonally in 4 triangular parts, yellow, blue, red, and black.

At the same time the F and L flags were slightly altered.

We have altered the flag F from a red pennant with a white ball on it to a red pennant with a white cross, as the flag at present in use is liable to be mistaken for Flag D (blue pennant with a white ball on it), and we have altered flag L from a flag of yellow and blue quarterly (the blue squares being at the top left-hand and bottom right-hand corners) to a flag of yellow and black quarterly, the black squares being at the top right-hand and bottom left-hand corners. Our chief reason for making this alteration is that in a calm it is difficult to distinguish the present flag L from flag K.

Certain of the above flags are used singly with special significations, viz. A by H.M. ships on full speed trial, B to signify that explosives are being landed or discharged, C as affirmative, D as negative, P to denote that the ship is about to sail and S as signal for a pilot, while L is used in the United Kingdom to indicate infection from cholera, Yellow fever or plague, and Q is generally used aboard to denote liability to quarantine.

Signals made with two flags are urgent and important. Of the three-flag signals those from ABC to AST relate to the compass; from ASU to AVJ to money; from AVK to BCN to weights and measures; BCO to BOZ to decimals and fractions; from BEA to CWT to auxiliary verbs and phrases; while the general vocabulary occupies the permutations from CXA to ZNV. The Code flag over two flags serves for Latitude and Longitude, Divisions of time, and the Barometer and Thermometer, and the Code flag under two flags from UA to ZY provides a numeral table. The geographical names of places are signalled by four flags from ABCD to BFAU, while the permutations from CBDF to CZYX are used for an alphabetical spelling table. This completes the flag signals of the Code, but it contains in addition a number of Distant Signals, Semaphore Signals and Morse Code Signals.

Combinations from GQBC onwards are used for the names of ships, which will be found in separate publications.