text: Passage of Lines
  * BHL.
  * Contact points.
  * Passage points.
  * Passage lanes
  * Routes.
  * Gaps.
  * Phase lines.
  * Recognition signals.
  * The headquarters directing the passage of lines designates or recommends:
  * Routes.
  * Start and end times for the passage of lines.
  Units may also use SPs, RPs, FSCMs such as CFLs, and other control measures as necessary to conduct this
  operation. Figure 16-1 depicts these control measures.
  Figure 16-1. Control measures associated with a rearward passage of lines
  16-10. The stationary unit establishes the necessary graphic control measures for the passage after
  coordination with the passing unit commander. The stationary unit establishes these measures because it
  controls the terrain. It knows the location of its obstacles and the tactical plan. In some cases, the higher
  echelon headquarters directing the passage may have previously established the necessary control measures.
  If the control measures dictated by the higher echelon headquarters are not sufficient—because they do not
  contain enough passage points, lanes, and so forth—the two units can agree to add the necessary measures
  and report to higher the additional control measures.