{ red 1/5 of width of flag St George's Cross { { white border 1/15 " " St Andrew's Cross { white 1/10 " " { red 1/15 " " St Patrick's Cross { { white border 1/30 " " It may be observed that the white "fimbriation" of the St Patrick's cross, required by the rules of heraldry to prevent the colour red from touching the colour blue (white being a "metal": silver) is now taken from the width of the red, reducing that from 1/10 to 1/15. The two crosses, St Andrew's and St Patrick's ought, however, to be of equal width, and the fimbriation of the latter should therefore be taken from the blue ground. In the white ensign the St George's cross in the fly is 2/15 of the width of the flag. In the red and blue ensigns the Union canton now occupies one-fourth of the flag; in the white it is, of course, slightly smaller owing to the space occupied by the large St George's cross. The pendant at the masthead of one of H.M. ships is a sign that the ship is in "commission"; that is, in active service under the command of an officer of the Royal Navy holding a commission from the Crown or the Lord High Admiral or the Commissioners for executing that office. It is not flown in ships in reserve. In ships flying the flag of an Admiral, or a Commodore's broad pendant, the Admiral's or Commodore's flag is in itself sufficient indication that the ship is in commission, and the pendant is not flown in those ships. It is, however, not struck when a captain hoists a Senior Officer's pendant. It is difficult to say when the custom of hoisting a pendant on commissioning the ship became established. Mainwaring, writing about 1623, speaks of the pendants as serving solely "for a show to beautify the ship," and Boteler, ten years later, knew them only as used for this purpose or as a means of distinguishing the squadrons of a fleet[413]; but from 1661 onwards there was, in addition to the three squadronal pendants with red, white or blue fly, a fourth with the fly striped red, white and blue. This was the distinctive pendant of all H.M. ships in commission which did not form part of a fleet divided into squadrons by the red, white and blue squadronal colours.