text: Glossary
  rearward passage of lines
  Occurs when a unit passes through another unit’s position while moving away from the enemy.
  (ADP 3-90)
  reconnaissance
  A mission undertaken to obtain information about the activities and resources of an enemy or
  adversary, or to secure data concerning the meteorological, hydrographic, geographic, or other
  characteristics of a particular area, by visual observation or other detection methods. (JP 2-0)
  *reconnaissance handover
  The action that occurs between two elements to coordinate the transfer of information and
  responsibility for observation of potential threat contact, or the transfer of an assigned area from one
  element to another.
  *reconnaissance handover line
  A designated phase line on the ground where reconnaissance responsibility transitions from one
  element to another.
  reconnaissance in force
  A type of reconnaissance operation designed to discover or test the enemy’s strength, dispositions, and
  reactions or to obtain other information. (ADP 3-90)
  rehearsal
  A session in which the commander and staff or unit practices expected actions to improve performance
  during execution. (ADP 5-0)
  relief in place
  An operation in which, by direction of higher authority, all or part of a unit is replaced in an area by
  the incoming unit and the responsibilities of the replaced elements for the mission and the assigned
  zone of operations are transferred to the incoming unit. (JP 3-07.3)
  reserve
  (Army) That portion of a body of troops that is withheld from action at the beginning of an engagement
  to be available for a decisive movement. (ADP 3-90)
  route reconnaissance
  A type of reconnaissance operation to obtain detailed information of a specified route and all terrain
  from which the enemy could influence movement along that route. (ADP 3-90)
  screen
  A type of security operation that primarily provides early warning to the protected force. (ADP 3-90)
  security cooperation
  Department of Defense interactions with foreign security establishments to build relationships that
  promote specific United States security interests, develop allied and partner military and security
  capabilities for self-defense and multinational operations, and provide United States forces with
  peacetime and contingency access to allies and partners. (JP 3-20)
  situational understanding
  The product of applying analysis and judgment to relevant information to determine the relationships
  among the operational and mission variables. (ADP 6-0)
  special reconnaissance
  Reconnaissance and surveillance actions conducted as a special operation in hostile, denied, or
  diplomatically and/or politically sensitive environments to collect or verify information of strategic or
  operational significance, employing military capabilities not normally found in conventional forces.
  (JP 3-05)
  surveillance
  The systematic observation of aerospace, cyberspace, surface, or subsurface areas, places, persons, or
  things by visual, aural, electronic, photographic, or other means. (JP 3-0)