text: Night Operations
  SIGNALS
  J-25. The team uses simple, familiar signals to pass information, identify locations, control formations,
  or initiate activity. Each basic signal has alternate signals as backups, and everyone must know these as
  well. Signaling at night helps the leader control what is happening. It supports security and surprise. It
  requires different methods than daylight signaling, for example, arm-and-hand signals might not be visible
  at night. The most common signals use sound, touch, and sight. The leader chooses signals based on the
  unit's activity and desired results, then he briefs the Soldiers and has them practice.
  AUDIO SIGNALS
  J-26. These include radio, wire, telephones, messengers, and grating or clicking of objects.
  Radio and Telephone Signals
  J-27. When using the radio and telephone at night, operators take precautions. They know that noise
  travels farther at night than during the day. They lower the volume as much as practical. They use
  headphones or earphones to reduce unnecessary noise. They know the possibility of loud static. They use
  signals such as breaking squelch a specified number of times.
  Messages
  J-28. Messengers carry written messages to avoid confusion and misinterpretation. When this is not
  possible, leaders ensure the messenger understands the message by having him repeat it word for word.
  Oral Signals
  K-1. Oral communication at night should be whispered. To do this, the Soldier takes a normal breath,
  exhales half of it, and then whispers into the other person's ear using the remainder of his breath.
  VISUAL SIGNALS
  J-29. These can be active or passive and include many options. For visual signals to work, everyone
  must see and recognize them.
  Passive Visual Signals
  • Sticks indicating direction.
  • Light-colored paint.
  • Tape.
  • Rock formations.
  • Markings on the ground.
  • Powder.
  Active Visual Signals
  • Flares.
  • Flashlights.
  • Illumination rounds (M203, mortar, artillery).
  • Chemical lights.
  • Infrared or incandescent strobe lights.
  • Either AN/PVS-5 or -7 night vision devices (infrared), or both.
  • Burning fuel (saturated sand in a can).
  • Luminous tape or compass dial.