Location of heavy artillery within supporting distance of front lines. Nuclear delivery
artillery is located within one-third of its maximum range from the line of contact on the offense,
and one-half on the defense.
Registration of heavy artillery. Registration may be required, using smoke, low-charge, or
high-explosive projectile, prior to firing a nuclear projectile.
Special or unusual activity by front-line troops. Front-line troops may construct special
positions, usually deep or covered foxholes, prior to enemy use of nuclear weapons.
Limited withdrawal of front-line units without apparent tactical reason. Front-line units
may withdraw for a limited distance to avoid casualties from close-in nuclear explosives.
Large concentrations of radios, radar, and other electronic equipment located in the
vicinity of suitable sites for guided missile launching. Concentration of equipment is
necessary to guide and control guided missiles, and must be located in close proximity of the
Sudden increase in communications and electronic activity. This increase may be
indicative of delivery and nuclear weapons. For example, last minute orders and warning, and
the use of electronic guidance and control.
Use of smoke cover on front-line troops. Smoke may be used to protect troops against
thermal effects of weapons used in close support.
Disappearance of known enemy agents from specific areas. Prior to nuclear attack of an
area, agents may be ordered to leave the area.
Increased or unusual air activity. Delivery of nuclear weapons by air may require a
temporary degree of local air superiority, special photo missions, or practice flight pattern runs
by the delivery aircraft.
2. Prisoners of War.
Prisoners of war (POW) can be valuable sources of information by their answers, such as those in the
other intelligence requirements (OIR) on page 1-1.3, and by the equipment and documents they may
be carrying when captured.