Practice varies from country to country as to the order in which the signal flags are placed on the "dressing lines": in some places a specific order is laid down,For the U.S. Navy the order of the flags, and the details of how and when the flags are displayed, is prescribed in . in others there is no such provision; either way, the intention is to produce a random succession of flags (i.e. not conveying any words or other messages), with the numerical and other pennants spaced equally and regularly along the line. Custom and regulations require that national or other flags not be mixed in with the signal flags when dressing a ship overall.
