text: Appendix A
  Gap
  A-23. A gap is an area free of obstacles that enables forces to maneuver in a
  tactical formation. It is wide enough to allow a friendly force to pass through while
  dispersed in a tactical formation. The presence of gaps prevents inadvertent
  concentrations of Soldiers and equipment around the entry points of lanes. Figure
  A-11 depicts the graphic control measure for a gap.
  Figure A-11. Gap
  Infiltration Lane
  A-24. An infiltration lane is a control measure that coordinates
  forward and lateral movement of infiltrating units and fixes fire
  planning responsibilities. Commanders select infiltration lanes that
  avoid enemy forces, provide cover and concealment, and facilitate
  navigation. Each unit assigned an infiltration lane picks its own routes
  within the lane and switches routes as necessary. The left and right
  limits of the infiltration lane act as lateral boundaries for the unit
  conducting the infiltration. Staffs must coordinate with the infiltrating
  unit any attacks by rotary- or fixed-wing aircraft, indirect fires, or
  munitions effects that impact the lane. Units leaving their assigned lane
  run the risk of impact by friendly fires. Company-sized units normally Figure A-12. Infiltration
  have a single infiltration lane, although they can use more than one lane MICHAEL
  lane. Larger organizations are always assigned more than one
  infiltration lane. Figure A-12 depicts the graphic control measure for INFILTRATION LANE MICHAEL.
  Line of Contact
  A-25. The line of contact is a general trace
  delineating the location where friendly and
  enemy forces are engaged. Units develop their
  line of contact (LC) based on the maximum
  effective range of the direct fire weapons systems
  or the visual line of sight from known or templated
  enemy locations. The commander designates the
  enemy side of the LC by the abbreviation “ENY.”
  In the defense, a LC is often synonymous with the
  FLOT. In the offense, commanders may combine
  the LC with the LD. When combined with the LD,
  it is represented by a phase line with LD/LC
  written next to the name. Figure A-19 on page A-
  11 depicts PL JOHN being used as a LD/LC.
  A-26. For other forms of contact, a phase line can
  be designated as a probable line of contact. For Figure A-13. Line of contact
  example, based on IPB and information collection
  friendly forces can depict known or anticipated locations of enemy artillery assets and determine a probable
  line of contact for enemy indirect fires. Figure A-13 shows an example line of contact.