diff --git a/common/src/main/scala/net/psforever/packet/game/ChildObjectStateMessage.scala b/common/src/main/scala/net/psforever/packet/game/ChildObjectStateMessage.scala
index 34e964c7..7e28c442 100644
--- a/common/src/main/scala/net/psforever/packet/game/ChildObjectStateMessage.scala
+++ b/common/src/main/scala/net/psforever/packet/game/ChildObjectStateMessage.scala
@@ -6,16 +6,26 @@ import scodec.Codec
 import scodec.codecs._
 
 /**
-  * na
+  * Dispatched from a client when its user is controlling a secondary object whose state must be updated.<br>
+  * <br>
+  * When `ChildObjectStateMessage` is being sent to the server, it replaces `PlayerStateMessage`.
+  * The packet frequently gets hidden in a `MultiPacket`, though it is not functionally essential to do that.<br>
+  * <br>
+  * Note the lack of position data.
+  * The secondary object in question is updated in position through another means or is stationary.
+  * The only concern is the direction the object is facing.
+  * The angles are relative to the object's normal forward-facing and typically begin tracking at 0, 0 (forward-facing).
   * @param object_guid the object being manipulated (controlled)
   * @param pitch the angle with respect to the sky and the ground towards which the object is directed;
   *              an 8-bit unsigned value;
-  *              0 is perfectly level and forward-facing, wrapping around at 255;
-  *              positive rotation is occurs by rotating downwards from forward-facing
+  *              0 is perfectly level and forward-facing and mapped to 255;
+  *              positive rotation is downwards from forward-facing;
+  *              between 7 (down) and 231 (up), for 32 angles
   * @param yaw the angle with respect to the horizon towards which the object is directed;
-  *              an 8-bit unsigned value;
-  *              0 is forward-facing, wrapping around at 255;
-  *              positive rotation is clockwise of forward-facing
+  *            an 8-bit unsigned value;
+  *            0 is forward-facing, wrapping around at 127;
+  *            positive rotation is counter-clockwise of forward-facing;
+  *            full rotation
   */
 final case class ChildObjectStateMessage(object_guid : PlanetSideGUID,
                                          pitch : Int,
diff --git a/common/src/test/scala/game/ChildObjectStateMessageTest.scala b/common/src/test/scala/game/ChildObjectStateMessageTest.scala
new file mode 100644
index 00000000..00cba45d
--- /dev/null
+++ b/common/src/test/scala/game/ChildObjectStateMessageTest.scala
@@ -0,0 +1,29 @@
+// Copyright (c) 2017 PSForever
+package game
+
+import org.specs2.mutable._
+import net.psforever.packet._
+import net.psforever.packet.game._
+import scodec.bits._
+
+class ChildObjectStateMessageTest extends Specification {
+  val string = hex"1E 640B 06 47"
+
+  "decode" in {
+    PacketCoding.DecodePacket(string).require match {
+      case ChildObjectStateMessage(object_guid, pitch, yaw) =>
+        object_guid mustEqual PlanetSideGUID(2916)
+        pitch mustEqual 6
+        yaw mustEqual 71
+      case _ =>
+        ko
+    }
+  }
+
+  "encode" in {
+    val msg = ChildObjectStateMessage(PlanetSideGUID(2916), 6, 71)
+    val pkt = PacketCoding.EncodePacket(msg).require.toByteVector
+
+    pkt mustEqual string
+  }
+}