Military forces of English-speaking countries often carry a pair of colors, one national or royal and the other of the unit itself. As distinguished from a standard, a color is used by foot units. Courtesy flag is the national flag of the country a merchant ship or yacht visits, hoisted as the ship enters port. Defacing differencing a flag by adding something to it, such as a charge, a badge, or writing. Used especially on colonial flags.
Device is an emblem or design, usually on the fly.
Differencing the design of a flag as a variation of another flag, either by changing a color, adding or removing a charge, etc. Usually done to indicate a close cultural, historical, or geographic tie. For example, the flag of Italy was differenced from that of France by changing the blue stripe to green. Dipping a method of saluting using a hand-held flag. The flagstaff is brought down to an almost horizontal level, with the flag almost trailing the ground, then raised smartly back to its original position.