signal is not hoisted to the dip; instead it is hoisted closed up after the signal is understood by the appropriate personnel. Question To question signals from the INCSEA agreement, the signal YVpl TACK ZLp3 will be used. Cancel To cancel signals from the INCSEA agreement, the code pennant followed by either YN or ZP must precede the group that cancels. SPECIAL WARNING SIGNALS To inform foreign naval vessels that they have violated Soviet spaces, will use the warning signals listed below: SNG SNO SNP SNR You have violated the state border of the Soviet Union. I demand that you leave Soviet Union waters immediately. I demand that you leave the waters of the Soviet Union immediately. Unless you do so, a force of arms will be used against you. You are violating the regulations for navigating and remaining in Soviet Union waters. I demand that you cease violations. Despite warnings, you continue to violate the regulations for navigating and remaining in Soviet Union waters. You are to leave them immediately. During the day, these signals will be made by flags. During nighttime, these signals are made by Morse code using a signal lamp. Radiotelephone may also be used to transmit the signal, as well as voice using a megaphone or any other amplifying device. WARNING SIGNALS TO SUBMARINES The signal of two series of explosions with three explosions in each series (where the interval between the explosions in a series is 1 minute and the interval between the series is 3 minutes) means “You are in Soviet Union waters. I demand you surface immediately. Unless you comply with this order within 10 minutes, a force of arms will be used against you.” An acoustic signal by sonar may be given simultaneously, with the same meaning as stated previously. The signal will consist of five dashes, each dash 3 seconds long, and the interval between dashes, 3 seconds. INDEX LEARNING OBJECTIVES: Explain the procedures for the use of the index. The index is divided into two separate indexes: Index 1 is the Signaling Instructions and General Signal Code and Index 2 is the Medical Signal Code. USE AND CONSTRUCTION OF GROUPS The types of signals used are the following: Single-letter signals—Indicate very urgent, important, or very common use Two-letter signals—The general code Three-letter signals—Begin with M and indicate the medical code The Code follows the basic principle that each signal should have a complete meaning. This principle is followed throughout the Code. In certain cases, complements are used when necessary to supplement the available group. To find a certain group when encoding, always turn first to the signal index or medical index, as appropriate, and pick out the key word or phase. Examples: Do you require a boat? KEY WORD: Boat Explosion has occurred in tank KEY WORD: Explosion COMPLEMENTS EXPRESS The use of complements is explained in the following paragraphs. You as a Signalman must know how to use complements to effectively communicate with merchantmen. Variations in the meaning of the basic signal: CP—I am (or vessel indicated is) proceeding to your assistance. 6-19