When a tanks or other units with offensive capabilities are selected and the cursor is placed over an enemy unit, the cursor will change to a target icon.  If the target icon appears as it does above, it means that the enemy is currently out of the selected units range.  If the attack order (right-click) is given, the unit will move within its attack range and fire.  The "in-range" target cursor appears as red cross-hairs. Notice the buttons on the bottom of the Toolbar (Stay, Tether, Pursue).  The first threeStay means that a unit will stay in its present location and fire at enemy units that come within range.  Tether (default) means that a unit will follow an enemy a short distance from its start point to attack it and then return to its start location.  Pursue means that a unit will chase an enemy until one of them have been destroyed or is out of its visual radius.

The next set of buttons are Guard, Attack, Move, Patrol, Return Fire and Stop.  A selected unit can be set to guard something by left-clicking on the "Guard" button and then right-clicking on the unit the player wishes it to guard.  The "Attack" button is used to force attack a unit or empty space on the map.  The "Move" button will force move a unit anywhere on the playfield, that might otherwise give it a different command icon (attack, etc.)  A selected unit can be set to patrol an area by selecting "Patrol" and then setting it's waypoints.  Waypoints can be set by holding "SHIFT" while right-clicking on the playfield.  A unit set to "Return Fire" will not shoot at an enemy unless it is first fired upon (useful for cloaked units).  The "Stop" button will stop any tasks or movement that the selected unit is performing.