Provides a rapid means of passing messages over short distances during daylight. The sender must always stand in a conspicuous position, choosing a plain, light background, the best of which is the skyline. The different semaphore signs are made by moving one or two flags, held by hand, so that they form various angles. It is essential that each angle be formed correctly and it is better to transmit slowly, as undue hurry in forming the letters will result in bad transmission and mistakes. Good communication depends on accuracy. The simplest method of remembering the signs, is to take them in a series of circles. 1st Circle: A to G (single arm signs). 2nd Circle: H to N (omitting 'J'). 3rd Circle: O to S. 4th Circle: T, U, Y. 5th Circle: Numeral sign, J and V. To complete: W, X, and Z. It should be noted that there are no special signs for numerals, which are always spelt out. The 'numeral sign' is used to indicate that the numeral(s) that will follow, are to be recorded as digits.