diff --git a/src/main/scala/net/psforever/actors/net/LoginActor.scala b/src/main/scala/net/psforever/actors/net/LoginActor.scala
index 6fd5d7bd5..f58fce6d1 100644
--- a/src/main/scala/net/psforever/actors/net/LoginActor.scala
+++ b/src/main/scala/net/psforever/actors/net/LoginActor.scala
@@ -106,7 +106,7 @@ class LoginActor(middlewareActor: typed.ActorRef[MiddlewareActor.Command], conne
 
         accountLogin(username, password.getOrElse(""))
 
-      case ConnectToWorldRequestMessage(name, _, _, _, _, _, _) =>
+      case ConnectToWorldRequestMessage(name, _, _, _, _, _, _, _) =>
         log.info(s"Connect to world request for '$name'")
         val response = ConnectToWorldMessage(serverName, publicAddress.getAddress.getHostAddress, publicAddress.getPort)
         middlewareActor ! MiddlewareActor.Send(response)
diff --git a/src/main/scala/net/psforever/actors/session/support/SessionData.scala b/src/main/scala/net/psforever/actors/session/support/SessionData.scala
index 74243d913..196bb8a15 100644
--- a/src/main/scala/net/psforever/actors/session/support/SessionData.scala
+++ b/src/main/scala/net/psforever/actors/session/support/SessionData.scala
@@ -156,7 +156,7 @@ class SessionData(
   /* packets */
 
   def handleConnectToWorldRequest(pkt: ConnectToWorldRequestMessage)(implicit context: ActorContext): Unit = {
-    val ConnectToWorldRequestMessage(_, token, majorVersion, minorVersion, revision, buildDate, _) = pkt
+    val ConnectToWorldRequestMessage(_, token, majorVersion, minorVersion, revision, buildDate, _, _) = pkt
     log.trace(
       s"ConnectToWorldRequestMessage: client with versioning $majorVersion.$minorVersion.$revision, $buildDate has sent a token to the server"
     )
@@ -217,9 +217,9 @@ class SessionData(
       }
     }
     fallHeightTracker(pos.z)
-    //        if (isCrouching && !player.Crouching) {
-    //          //dev stuff goes here
-    //        }
+//    if (isCrouching && !player.Crouching) {
+//      //dev stuff goes here
+//    }
     player.Position = pos
     player.Velocity = vel
     player.Orientation = Vector3(player.Orientation.x, pitch, yaw)
diff --git a/src/main/scala/net/psforever/objects/definition/converter/BattleFrameFlightConverter.scala b/src/main/scala/net/psforever/objects/definition/converter/BattleFrameFlightConverter.scala
index 49fcd57c7..0d652db9e 100644
--- a/src/main/scala/net/psforever/objects/definition/converter/BattleFrameFlightConverter.scala
+++ b/src/main/scala/net/psforever/objects/definition/converter/BattleFrameFlightConverter.scala
@@ -4,7 +4,7 @@ package net.psforever.objects.definition.converter
 import net.psforever.objects.equipment.{Equipment, EquipmentSlot}
 import net.psforever.objects.vehicles.VehicleSubsystemEntry
 import net.psforever.objects.{PlanetSideGameObject, Vehicle}
-import net.psforever.types.PlanetSideGUID
+import net.psforever.types.{PlanetSideGUID, VehicleFormat}
 import net.psforever.packet.game.objectcreate._
 
 import scala.util.{Failure, Success, Try}
diff --git a/src/main/scala/net/psforever/objects/definition/converter/BattleFrameRoboticsConverter.scala b/src/main/scala/net/psforever/objects/definition/converter/BattleFrameRoboticsConverter.scala
index 0f94dfc9c..1c51b1afb 100644
--- a/src/main/scala/net/psforever/objects/definition/converter/BattleFrameRoboticsConverter.scala
+++ b/src/main/scala/net/psforever/objects/definition/converter/BattleFrameRoboticsConverter.scala
@@ -4,7 +4,7 @@ package net.psforever.objects.definition.converter
 import net.psforever.objects.equipment.{Equipment, EquipmentSlot}
 import net.psforever.objects.vehicles.VehicleSubsystemEntry
 import net.psforever.objects.{PlanetSideGameObject, Vehicle}
-import net.psforever.types.PlanetSideGUID
+import net.psforever.types.{PlanetSideGUID, VehicleFormat}
 import net.psforever.packet.game.objectcreate._
 
 import scala.util.{Failure, Success, Try}
diff --git a/src/main/scala/net/psforever/objects/definition/converter/SeatConverter.scala b/src/main/scala/net/psforever/objects/definition/converter/SeatConverter.scala
index dfa7d5b20..2ccc8788c 100644
--- a/src/main/scala/net/psforever/objects/definition/converter/SeatConverter.scala
+++ b/src/main/scala/net/psforever/objects/definition/converter/SeatConverter.scala
@@ -11,7 +11,7 @@ object SeatConverter {
       AvatarConverter.MakeAppearanceData(player),
       AvatarConverter.MakeCharacterData(player),
       AvatarConverter.MakeInventoryData(player),
-      AvatarConverter.GetDrawnSlot(player),
+      DrawnSlot.None,
       offset
     )
   }
diff --git a/src/main/scala/net/psforever/objects/definition/converter/UtilityVehicleConverter.scala b/src/main/scala/net/psforever/objects/definition/converter/UtilityVehicleConverter.scala
index d3ddd5ea9..61812407c 100644
--- a/src/main/scala/net/psforever/objects/definition/converter/UtilityVehicleConverter.scala
+++ b/src/main/scala/net/psforever/objects/definition/converter/UtilityVehicleConverter.scala
@@ -2,10 +2,11 @@
 package net.psforever.objects.definition.converter
 
 import net.psforever.objects.Vehicle
-import net.psforever.packet.game.objectcreate.{UtilityVehicleData, VehicleFormat}
+import net.psforever.packet.game.objectcreate.UtilityVehicleData
+import net.psforever.types.VehicleFormat
 
 class UtilityVehicleConverter extends VehicleConverter {
-  override protected def SpecificFormatModifier: VehicleFormat.Value = VehicleFormat.Utility
+  override protected def SpecificFormatModifier: VehicleFormat = VehicleFormat.Utility
 
-  override protected def SpecificFormatData(obj: Vehicle) = Some(UtilityVehicleData(0))
+  override protected def SpecificFormatData(obj: Vehicle): Some[UtilityVehicleData] = Some(UtilityVehicleData(0))
 }
diff --git a/src/main/scala/net/psforever/objects/definition/converter/VariantVehicleConverter.scala b/src/main/scala/net/psforever/objects/definition/converter/VariantVehicleConverter.scala
index ed972465f..9b07c88c8 100644
--- a/src/main/scala/net/psforever/objects/definition/converter/VariantVehicleConverter.scala
+++ b/src/main/scala/net/psforever/objects/definition/converter/VariantVehicleConverter.scala
@@ -2,12 +2,13 @@
 package net.psforever.objects.definition.converter
 
 import net.psforever.objects.Vehicle
-import net.psforever.packet.game.objectcreate.{VariantVehicleData, VehicleFormat}
+import net.psforever.packet.game.objectcreate.VariantVehicleData
+import net.psforever.types.VehicleFormat
 
 class VariantVehicleConverter extends VehicleConverter {
-  override protected def SpecificFormatModifier: VehicleFormat.Value = VehicleFormat.Variant
+  override protected def SpecificFormatModifier: VehicleFormat = VehicleFormat.Variant
 
-  override protected def SpecificFormatData(obj: Vehicle) = {
+  override protected def SpecificFormatData(obj: Vehicle): Some[VariantVehicleData] = {
     /*
     landed is 0
     flying is 7
diff --git a/src/main/scala/net/psforever/objects/definition/converter/VehicleConverter.scala b/src/main/scala/net/psforever/objects/definition/converter/VehicleConverter.scala
index 2e76d7314..6ce558c2e 100644
--- a/src/main/scala/net/psforever/objects/definition/converter/VehicleConverter.scala
+++ b/src/main/scala/net/psforever/objects/definition/converter/VehicleConverter.scala
@@ -4,7 +4,7 @@ package net.psforever.objects.definition.converter
 import net.psforever.objects.equipment.{Equipment, EquipmentSlot}
 import net.psforever.objects.{PlanetSideGameObject, Vehicle}
 import net.psforever.packet.game.objectcreate._
-import net.psforever.types.{DriveState, PlanetSideGUID}
+import net.psforever.types.{DriveState, PlanetSideGUID, VehicleFormat}
 
 import scala.util.{Failure, Success, Try}
 
@@ -75,9 +75,9 @@ class VehicleConverter extends ObjectCreateConverter[Vehicle]() {
   }
 
   private def MakeDriverSeat(obj: Vehicle): List[InventoryItemData.InventoryItem] = {
-    val offset: Long = MountableInventory.InitialStreamLengthToSeatEntries(obj.Velocity.nonEmpty, SpecificFormatModifier)
     obj.Seats(0).occupant match {
       case Some(player) =>
+        val offset: Long = MountableInventory.InitialStreamLengthToSeatEntries(obj.Velocity.nonEmpty, SpecificFormatModifier)
         List(InventoryItemData(ObjectClass.avatar, player.GUID, 0, SeatConverter.MakeSeat(player, offset)))
       case None =>
         Nil
@@ -112,7 +112,7 @@ class VehicleConverter extends ObjectCreateConverter[Vehicle]() {
     }
   }
 
-  protected def SpecificFormatModifier: VehicleFormat.Value = VehicleFormat.Normal
+  protected def SpecificFormatModifier: VehicleFormat = VehicleFormat.Normal
 
   protected def SpecificFormatData(obj: Vehicle): Option[SpecificVehicleData] = None
 }
diff --git a/src/main/scala/net/psforever/packet/game/ConnectToWorldRequestMessage.scala b/src/main/scala/net/psforever/packet/game/ConnectToWorldRequestMessage.scala
index 63b0aadd5..36193896b 100644
--- a/src/main/scala/net/psforever/packet/game/ConnectToWorldRequestMessage.scala
+++ b/src/main/scala/net/psforever/packet/game/ConnectToWorldRequestMessage.scala
@@ -14,7 +14,8 @@ final case class ConnectToWorldRequestMessage(
     minorVersion: Long,
     revision: Long,
     buildDate: String,
-    unknown: Int
+    unk1: Int,
+    unk2: Int
 ) extends PlanetSideGamePacket {
   type Packet = ConnectToWorldRequestMessage
   def opcode = GamePacketOpcode.ConnectToWorldRequestMessage
@@ -29,6 +30,7 @@ object ConnectToWorldRequestMessage extends Marshallable[ConnectToWorldRequestMe
       ("minor_version" | uint32L) ::
       ("revision" | uint32L) ::
       ("build_date" | PacketHelpers.encodedString) ::
-      ("unknown_short" | uint16L)
+      ("unk1" | uint8) ::
+      ("unk2" | uint8)
   ).as[ConnectToWorldRequestMessage]
 }
diff --git a/src/main/scala/net/psforever/packet/game/objectcreate/BattleFrameRoboticsData.scala b/src/main/scala/net/psforever/packet/game/objectcreate/BattleFrameRoboticsData.scala
index 03c4692b5..a0e63db6d 100644
--- a/src/main/scala/net/psforever/packet/game/objectcreate/BattleFrameRoboticsData.scala
+++ b/src/main/scala/net/psforever/packet/game/objectcreate/BattleFrameRoboticsData.scala
@@ -2,6 +2,7 @@
 package net.psforever.packet.game.objectcreate
 
 import net.psforever.packet.Marshallable
+import net.psforever.types.VehicleFormat
 import scodec.{Attempt, Codec, Err}
 import shapeless.HNil
 import scodec.codecs._
diff --git a/src/main/scala/net/psforever/packet/game/objectcreate/CharacterAppearanceData.scala b/src/main/scala/net/psforever/packet/game/objectcreate/CharacterAppearanceData.scala
index 08018cf7a..3e8b820e1 100644
--- a/src/main/scala/net/psforever/packet/game/objectcreate/CharacterAppearanceData.scala
+++ b/src/main/scala/net/psforever/packet/game/objectcreate/CharacterAppearanceData.scala
@@ -171,9 +171,9 @@ object CharacterAppearanceData extends Marshallable[CharacterAppearanceData] {
         app.faction,
         black_ops,
         altModel,
-        false,
+        v1 = false,
         None,
-        false,
+        jammered=false,
         None,
         if (jammered) {
           Some(0)
@@ -194,20 +194,20 @@ object CharacterAppearanceData extends Marshallable[CharacterAppearanceData] {
       outfit_name.length,
       outfit_name: String,
       outfit_logo: Int,
-      false,
+      unk1 = false,
       backpack,
-      false,
-      false,
-      false,
+      unk2 = false,
+      unk3 = false,
+      unk4 = false,
       facingPitch: Float,
       facingYawUpper: Float,
       lfs: Boolean,
       grenade_state: GrenadeState.Value,
       is_cloaking: Boolean,
-      false,
-      false,
+      unk5 = false,
+      unk6 = false,
       charging_pose: Boolean,
-      false,
+      unk7 = false,
       on_zipline
     )(altModel, name_padding)
     new CharacterAppearanceData(
@@ -283,11 +283,6 @@ object CharacterAppearanceData extends Marshallable[CharacterAppearanceData] {
     6
   }
 
-  private val extra_codec: Codec[ExtraData] = (
-    ("unk1" | bool) ::
-      ("unk2" | bool)
-  ).as[ExtraData]
-
   private val zipline_codec: Codec[ZiplineData] = (
     ("unk1" | uint32L) ::
       ("unk2" | bool)
@@ -303,7 +298,7 @@ object CharacterAppearanceData extends Marshallable[CharacterAppearanceData] {
       ("data" | CommonFieldData.codec) >>:~ { data =>
         ("name" | PacketHelpers.encodedWideStringAligned(namePadding(name_padding, data.v2))) ::
           ("exosuit" | ExoSuitType.codec) ::
-          ("unk5" | uint2) :: //unknown
+          ("unk5" | uint2) ::
           ("sex" | CharacterSex.codec) ::
           ("head" | uint8L) ::
           ("voice" | CharacterVoice.codec) ::
@@ -398,14 +393,14 @@ object CharacterAppearanceData extends Marshallable[CharacterAppearanceData] {
         ("outfit_name" | PacketHelpers.encodedWideStringAligned(outfitNamePadding)) ::
         ("outfit_logo" | uint8L) ::
         ("unk1" | bool) ::                           //unknown
-        conditional(alt_model, "backpack" | bool) :: //alt_model flag adds this bit; see ps.c:line#1069587
+        ("backpack" | conditional(alt_model, bool)) :: //alt_model flag adds this bit; see ps.c:line#1069587
         ("unk2" | bool) ::                           //requires alt_model flag (does NOT require health == 0)
         ("unk3" | bool) ::                           //stream misalignment when set
         ("unk4" | bool) ::                           //unknown
         ("facingPitch" | Angular.codec_zero_centered) ::
         ("facingYawUpper" | Angular.codec_zero_centered) ::
         ("lfs" | uint2) ::
-        ("grenade_state" | GrenadeState.codec_2u) :: //note: bin10 and bin11 are neutral (bin00 is not defined)
+        ("grenade_state" | GrenadeState.codec_2u) ::
         ("is_cloaking" | bool) ::
         ("unk5" | bool) :: //unknown
         ("unk6" | bool) :: //stream misalignment when set
diff --git a/src/main/scala/net/psforever/packet/game/objectcreate/CharacterData.scala b/src/main/scala/net/psforever/packet/game/objectcreate/CharacterData.scala
index 014c46bd9..d224f62d5 100644
--- a/src/main/scala/net/psforever/packet/game/objectcreate/CharacterData.scala
+++ b/src/main/scala/net/psforever/packet/game/objectcreate/CharacterData.scala
@@ -119,7 +119,7 @@ object CharacterData extends Marshallable[CharacterData] {
       ("health" | uint8L) :: //dead state when health == 0
         ("armor" | uint8L) ::
         (("uniform_upgrade" | UniformStyle.codec) >>:~ { style =>
-        uint(3) :: //uniform_upgrade is actually interpreted as a 6u field, but the lower 3u seems to be discarded
+        uint(bits = 3) :: //uniform_upgrade is actually interpreted as a 6u field, but the lower 3u seems to be discarded
           ("command_rank" | uintL(3)) ::
           listOfN(uint2, "implant_effects" | ImplantEffects.codec) ::
           ("cosmetics" | conditional(BattleRank.showCosmetics(style), Cosmetic.codec))
diff --git a/src/main/scala/net/psforever/packet/game/objectcreate/MountableInventory.scala b/src/main/scala/net/psforever/packet/game/objectcreate/MountableInventory.scala
index 8e883c7ba..76d2c50a3 100644
--- a/src/main/scala/net/psforever/packet/game/objectcreate/MountableInventory.scala
+++ b/src/main/scala/net/psforever/packet/game/objectcreate/MountableInventory.scala
@@ -2,7 +2,7 @@
 package net.psforever.packet.game.objectcreate
 
 import net.psforever.packet.PacketHelpers
-import net.psforever.types.PlanetSideGUID
+import net.psforever.types.{PlanetSideGUID, VehicleFormat}
 import scodec.Attempt.{Failure, Successful}
 import scodec.{Codec, Err}
 import scodec.codecs._
@@ -23,7 +23,7 @@ object MountableInventory {
   * @param format the subtype for this vehicle
   * @return a `Codec` that translates `InventoryData`
   */
-  def custom_inventory_codec(hasVelocity: Boolean, format: VehicleFormat.Type): Codec[InventoryData] =
+  def custom_inventory_codec(hasVelocity: Boolean, format: VehicleFormat): Codec[InventoryData] =
     custom_inventory_codec(InitialStreamLengthToSeatEntries(hasVelocity, format))
 
   /**
@@ -96,7 +96,7 @@ object MountableInventory {
                   accumulative: Long
                 ): Player_Data = {
     val appearance = basic_appearance(CumulativeSeatedPlayerNamePadding(accumulative))
-    Player_Data(None, appearance, character_data(appearance.b.backpack, true), Some(inventory), drawn_slot)(false)
+    Player_Data(None, appearance, character_data(false, true), Some(inventory), drawn_slot)(position_defined = false)
   }
 
   /**
@@ -118,7 +118,7 @@ object MountableInventory {
                   accumulative: Long
                 ): Player_Data = {
     val appearance = basic_appearance(CumulativeSeatedPlayerNamePadding(accumulative))
-    Player_Data.apply(None, appearance, character_data(appearance.b.backpack, true), None, drawn_slot)(false)
+    Player_Data.apply(None, appearance, character_data(false, true), None, drawn_slot)(position_defined = false)
   }
 
   /**
@@ -136,16 +136,8 @@ object MountableInventory {
     * @param format the subtype for this vehicle
     * @return the length of the bitstream
     */
-  def InitialStreamLengthToSeatEntries(hasVelocity: Boolean, format: VehicleFormat.Type): Long = {
-    198 +
-    (if (hasVelocity) 42 else 0) +
-    (format match {
-      case VehicleFormat.Utility           => 6
-      case VehicleFormat.Variant           => 8
-      case VehicleFormat.Battleframe       => 1
-      case VehicleFormat.BattleframeFlight => 2
-      case _                               => 0
-    })
+  def InitialStreamLengthToSeatEntries(hasVelocity: Boolean, format: VehicleFormat): Long = {
+    198 + (if (hasVelocity) 42 else 0) + format.value
   }
 
   /**
@@ -156,10 +148,7 @@ object MountableInventory {
     * @return the padding value, 0-7 bits
     */
   def CumulativeSeatedPlayerNamePadding(base: Long, next: Option[StreamBitSize]): Int = {
-    CumulativeSeatedPlayerNamePadding(base + (next match {
-      case Some(o) => o.bitsize
-      case None    => 0
-    }))
+    CumulativeSeatedPlayerNamePadding(base + next.map { _.bitsize }.getOrElse(0L))
   }
 
   /**
@@ -199,7 +188,7 @@ object MountableInventory {
   private def inventory_seat_codec(length: Long, offset: Int): Codec[Option[InventorySeat]] = {
     import shapeless.::
     (
-      PacketHelpers.peek(uintL(11)) >>:~ { objClass =>
+      PacketHelpers.peek(uintL(bits = 11)) >>:~ { objClass =>
         conditional(objClass == ObjectClass.avatar, seat_codec(offset)) >>:~ { seat =>
           conditional(
             objClass == ObjectClass.avatar,
@@ -240,7 +229,7 @@ object MountableInventory {
   }
 
   /**
-    * Translate data the is verified to involve a player who is seated (mounted) to the parent object at a given slot.
+    * Translate data that is verified to involve a player who is seated (mounted) to the parent object at a given slot.
     * The operation performed by this `Codec` is very similar to `InternalSlot.codec`.
     * @param pad the padding offset for the player's name;
     *            0-7 bits;
@@ -253,7 +242,7 @@ object MountableInventory {
   private def seat_codec(pad: Int): Codec[InternalSlot] = {
     import shapeless.::
     (
-      ("objectClass" | uintL(11)) ::
+      ("objectClass" | uintL(bits = 11)) ::
       ("guid" | PlanetSideGUID.codec) ::
       ("parentSlot" | PacketHelpers.encodedStringSize) ::
       ("obj" | Player_Data.codec(pad))
diff --git a/src/main/scala/net/psforever/packet/game/objectcreate/ObjectClass.scala b/src/main/scala/net/psforever/packet/game/objectcreate/ObjectClass.scala
index 25a20a14d..224e1e896 100644
--- a/src/main/scala/net/psforever/packet/game/objectcreate/ObjectClass.scala
+++ b/src/main/scala/net/psforever/packet/game/objectcreate/ObjectClass.scala
@@ -1,6 +1,7 @@
 // Copyright (c) 2017 PSForever
 package net.psforever.packet.game.objectcreate
 
+import net.psforever.types.VehicleFormat
 import scodec.{Attempt, Codec, Err}
 import scodec.codecs._
 
diff --git a/src/main/scala/net/psforever/packet/game/objectcreate/VehicleData.scala b/src/main/scala/net/psforever/packet/game/objectcreate/VehicleData.scala
index 6e912423a..c4f2921c3 100644
--- a/src/main/scala/net/psforever/packet/game/objectcreate/VehicleData.scala
+++ b/src/main/scala/net/psforever/packet/game/objectcreate/VehicleData.scala
@@ -6,21 +6,12 @@ import scodec.Attempt.{Failure, Successful}
 import scodec.{Attempt, Codec, Err}
 import shapeless.HNil
 import scodec.codecs._
-import net.psforever.types.DriveState
-
-/**
-  * An `Enumeration` of the various formats that known structures that the stream of bits for `VehicleData` can assume.
-  */
-object VehicleFormat extends Enumeration {
-  type Type = Value
-
-  val Battleframe, BattleframeFlight, Normal, Utility, Variant = Value
-}
+import net.psforever.types.{DriveState, VehicleFormat}
 
 /**
   * A basic `Trait` connecting all of the vehicle data formats (excepting `Normal`/`None`).
   */
-sealed abstract class SpecificVehicleData(val format: VehicleFormat.Value) extends StreamBitSize
+sealed abstract class SpecificVehicleData(val format: VehicleFormat) extends StreamBitSize
 
 /**
   * The format of vehicle data for the type of vehicles that are considered "utility."
@@ -84,7 +75,7 @@ final case class VehicleData(
     cloak: Boolean,
     vehicle_format_data: Option[SpecificVehicleData],
     inventory: Option[InventoryData] = None
-)(val vehicle_type: VehicleFormat.Value = VehicleFormat.Normal)
+)(val vehicle_type: VehicleFormat = VehicleFormat.Normal)
     extends ConstructorData {
   override def bitsize: Long = {
     //factor guard bool values into the base size, not its corresponding optional field
@@ -174,7 +165,7 @@ object VehicleData extends Marshallable[VehicleData] {
     */
   private val utility_data_codec: Codec[SpecificVehicleData] = {
     import shapeless.::
-    uintL(6).hlist.exmap[SpecificVehicleData](
+    uintL(VehicleFormat.Utility.value).hlist.exmap[SpecificVehicleData](
       {
         case n :: HNil =>
           Successful(UtilityVehicleData(n).asInstanceOf[SpecificVehicleData])
@@ -193,7 +184,7 @@ object VehicleData extends Marshallable[VehicleData] {
     */
   private val variant_data_codec: Codec[SpecificVehicleData] = {
     import shapeless.::
-    uint8L.hlist.exmap[SpecificVehicleData](
+    uintL(VehicleFormat.Variant.value).hlist.exmap[SpecificVehicleData](
       {
         case n :: HNil =>
           Successful(VariantVehicleData(n).asInstanceOf[SpecificVehicleData])
@@ -212,7 +203,7 @@ object VehicleData extends Marshallable[VehicleData] {
     * @param vehicleFormat the requested format
     * @return the appropriate `Codec` for parsing that format
     */
-  private def selectFormatReader(vehicleFormat: VehicleFormat.Value): Codec[SpecificVehicleData] =
+  private def selectFormatReader(vehicleFormat: VehicleFormat): Codec[SpecificVehicleData] =
     vehicleFormat match {
       case VehicleFormat.Utility =>
         utility_data_codec
@@ -223,7 +214,7 @@ object VehicleData extends Marshallable[VehicleData] {
           .asInstanceOf[Codec[SpecificVehicleData]]
     }
 
-  def codec(vehicle_type: VehicleFormat.Value): Codec[VehicleData] = {
+  def codec(vehicle_type: VehicleFormat): Codec[VehicleData] = {
     import shapeless.::
     (
       ("pos" | PlacementData.codec) >>:~ { pos =>
@@ -237,7 +228,7 @@ object VehicleData extends Marshallable[VehicleData] {
         ("unk6" | bool) ::
         ("cloak" | bool) :: //cloak as wraith, phantasm
         conditional(vehicle_type != VehicleFormat.Normal,"vehicle_format_data" | selectFormatReader(vehicle_type)) ::
-        optional(bool, target = "inventory" | MountableInventory.custom_inventory_codec(pos.vel.isDefined, VehicleFormat.Normal))
+        optional(bool, target = "inventory" | MountableInventory.custom_inventory_codec(pos.vel.isDefined, vehicle_type))
       }
     ).exmap[VehicleData](
       {
diff --git a/src/main/scala/net/psforever/types/CharacterVoice.scala b/src/main/scala/net/psforever/types/CharacterVoice.scala
index a6e287d44..eefc6baa2 100644
--- a/src/main/scala/net/psforever/types/CharacterVoice.scala
+++ b/src/main/scala/net/psforever/types/CharacterVoice.scala
@@ -22,5 +22,5 @@ object CharacterVoice extends Enumeration {
   Voice5            //daredevil, calculating
   = Value
 
-  implicit val codec = PacketHelpers.createEnumerationCodec(this, uint(3))
+  implicit val codec = PacketHelpers.createEnumerationCodec(this, uint(bits = 3))
 }
diff --git a/src/main/scala/net/psforever/types/ExoSuitType.scala b/src/main/scala/net/psforever/types/ExoSuitType.scala
index fee36b081..439d1e023 100644
--- a/src/main/scala/net/psforever/types/ExoSuitType.scala
+++ b/src/main/scala/net/psforever/types/ExoSuitType.scala
@@ -12,5 +12,5 @@ object ExoSuitType extends Enumeration {
   type Type = Value
   val Agile, Reinforced, MAX, Infiltration, Standard = Value
 
-  implicit val codec: Codec[ExoSuitType.Value] = PacketHelpers.createEnumerationCodec(this, uint(3))
+  implicit val codec: Codec[ExoSuitType.Value] = PacketHelpers.createEnumerationCodec(this, uint(bits = 3))
 }
diff --git a/src/main/scala/net/psforever/types/GrenadeState.scala b/src/main/scala/net/psforever/types/GrenadeState.scala
index a75e0c9e5..6242cbd4d 100644
--- a/src/main/scala/net/psforever/types/GrenadeState.scala
+++ b/src/main/scala/net/psforever/types/GrenadeState.scala
@@ -7,12 +7,14 @@ import scodec.codecs._
 /**
   * An `Enumeration` of the kinds of states applicable to the grenade animation.
   */
-object GrenadeState extends Enumeration(1) {
+object GrenadeState extends Enumeration {
   type Type = Value
 
-  val Primed, //avatars and other depicted player characters
-  Thrown,     //avatars only
-  None        //non-actionable state of rest
+  val
+  Non,    //non-actionable state of rest
+  Primed, //avatars and other depicted player characters
+  Thrown, //avatars only
+  None    //non-actionable state of rest
   = Value
 
   implicit val codec = PacketHelpers.createEnumerationCodec(this, uint8L)
diff --git a/src/main/scala/net/psforever/types/VehicleFormat.scala b/src/main/scala/net/psforever/types/VehicleFormat.scala
new file mode 100644
index 000000000..30cf9b099
--- /dev/null
+++ b/src/main/scala/net/psforever/types/VehicleFormat.scala
@@ -0,0 +1,19 @@
+// Copyright (c) 2023 PSForever
+package net.psforever.types
+
+import enumeratum.values.{IntEnum, IntEnumEntry}
+
+/**
+ * An enumeration of the various formats that known structures that the stream of bits for `VehicleData` can assume.
+ */
+sealed abstract class VehicleFormat(val value: Int) extends IntEnumEntry
+
+object VehicleFormat extends IntEnum[VehicleFormat] {
+  val values: IndexedSeq[VehicleFormat] = findValues
+
+  case object Normal extends VehicleFormat(value = 0)
+  case object Battleframe extends VehicleFormat(value = 1)
+  case object BattleframeFlight extends VehicleFormat(value = 2)
+  case object Utility extends VehicleFormat(value = 6)
+  case object Variant extends VehicleFormat(value = 8)
+}
diff --git a/src/test/scala/game/ConnectToWorldRequestMessageTest.scala b/src/test/scala/game/ConnectToWorldRequestMessageTest.scala
index 770bb3aca..05f1dba0e 100644
--- a/src/test/scala/game/ConnectToWorldRequestMessageTest.scala
+++ b/src/test/scala/game/ConnectToWorldRequestMessageTest.scala
@@ -12,21 +12,22 @@ class ConnectToWorldRequestMessageTest extends Specification {
 
   "decode" in {
     PacketCoding.decodePacket(string).require match {
-      case ConnectToWorldRequestMessage(serverName, token, majorVersion, minorVersion, revision, buildDate, unk) =>
+      case ConnectToWorldRequestMessage(serverName, token, majorVersion, minorVersion, revision, buildDate, unk1, unk2) =>
         serverName mustEqual "gemini"
         token mustEqual ""
         majorVersion mustEqual 0
         minorVersion mustEqual 0
         revision mustEqual 0
         buildDate mustEqual ""
-        unk mustEqual 0
+        unk1 mustEqual 0
+        unk2 mustEqual 0
       case _ =>
         ko
     }
   }
 
   "encode" in {
-    val msg = ConnectToWorldRequestMessage("gemini", "", 0, 0, 0, "", 0)
+    val msg = ConnectToWorldRequestMessage("gemini", "", 0, 0, 0, "", 0, 0)
     val pkt = PacketCoding.encodePacket(msg).require.toByteVector
 
     pkt mustEqual string
diff --git a/src/test/scala/game/objectcreatevehicle/UtilityVehiclesTest.scala b/src/test/scala/game/objectcreatevehicle/UtilityVehiclesTest.scala
index b6bec222d..57dedbdb0 100644
--- a/src/test/scala/game/objectcreatevehicle/UtilityVehiclesTest.scala
+++ b/src/test/scala/game/objectcreatevehicle/UtilityVehiclesTest.scala
@@ -2,7 +2,7 @@
 package game.objectcreatevehicle
 
 import net.psforever.packet._
-import net.psforever.packet.game.objectcreate._
+import net.psforever.packet.game.objectcreate.{CharacterAppearanceA, _}
 import net.psforever.packet.game.ObjectCreateMessage
 import net.psforever.types._
 import org.specs2.mutable._
@@ -12,8 +12,8 @@ class UtilityVehiclesTest extends Specification {
   val string_ant = hex"17 C2000000 9E0 7C01 6C2D7 65535 CA16 00 00 00 4400003FC000000"
   val string_ams =
     hex"17 B8010000 970 3D10 002D765535CA16000000 402285BB0037E4100749E1D03000000620D83A0A00000195798741C00000332E40D84800000"
-//  val string_ams_seated =
-//    hex"17ec060000970fe0f030898abda28127f007ff9c1f2f80c0001e18ff00001051e40786400000008c50004c0041006d0069006e006700790075006500540052007c00000304217c859e8080000000000000002503420022c02a002a002a002a0050004c0041002a002a002a002a00010027e300940000016c0400023c040002285a086c2f00c80000000000300210288740800000004046f17423018000002c4d6190400000001010704a86406000002bc770842000000004041c5f21d01800000e075821902000000623e84208000001950588c1800000332ea0f840000000"
+  val string_ams_seated =
+    hex"17 ec060000 970 fe0f 6C2D765535CA16000013 f9c1f2f80c000 1e18ff0000 105 1e4078640000000 8c50004c0041006d0069006e00670079007500650054005200 04217c859e808000000000000000250342002 2c02a002a002a002a0050004c0041002a002a002a002a00 010027e3007c000003940000016c0400023c040002285a086c2f00c80000000000300210288740800000004046f17423018000002c4d6190400000001010704a86406000002bc770842000000004041c5f21d01800000e0 75821902000000 623e8420800000 1950588c1800000 332ea0f840000000"
 
   "Utility vehicles" should {
     "decode (ant)" in {
@@ -95,6 +95,152 @@ class UtilityVehiclesTest extends Specification {
       }
     }
 
+    "decode (ams, seated)" in {
+      PacketCoding.decodePacket(string_ams_seated).require match {
+        case ObjectCreateMessage(len, cls, guid, None, data) =>
+          len mustEqual 1772
+          cls mustEqual ObjectClass.ams
+          guid mustEqual PlanetSideGUID(4094)
+          data match {
+            case ams: VehicleData =>
+              ams.pos.coord mustEqual Vector3(3674.8438f, 2726.789f, 91.15625f)
+              ams.pos.orient mustEqual Vector3(0f, 0f, 36.5625f)
+              ams.pos.vel.contains(Vector3(27.3375f, -0.78749996f, 0.1125f)) mustEqual true //contains does not work
+              ams.data match {
+                case data: CommonFieldData =>
+                  data.faction mustEqual PlanetSideEmpire.TR
+                  data.bops mustEqual false
+                  data.alternate mustEqual false
+                  data.v1 mustEqual false
+                  data.v2.isEmpty mustEqual true
+                  data.jammered mustEqual false
+                  data.v4.contains(false) mustEqual true
+                  data.v5.isEmpty mustEqual true
+                  data.guid mustEqual ValidPlanetSideGUID(3087)
+                case _ =>
+                  ko
+              }
+              ams.unk3 mustEqual false
+              ams.health mustEqual 255
+              ams.unk4 mustEqual false
+              ams.no_mount_points mustEqual false
+              ams.driveState mustEqual DriveState.Mobile
+              ams.unk5 mustEqual false
+              ams.unk6 mustEqual false
+              ams.cloak mustEqual false
+              ams.vehicle_format_data.contains(UtilityVehicleData(0)) mustEqual true
+              val inv = ams.inventory match {
+                case Some(inv: InventoryData) => inv.contents
+                case _ => Nil
+              }
+              //0
+              val inv0 = inv.head
+              inv0.objectClass mustEqual ObjectClass.avatar
+              inv0.guid mustEqual PlanetSideGUID(3087)
+              inv0.parentSlot mustEqual 0
+              inv0.obj match {
+                case PlayerData(None, CharacterAppearanceData(a, b, r), char, Some(InventoryData(pinv)), DrawnSlot.None) =>
+                  a.app.name mustEqual "PLAmingyueTR"
+                  a.app.faction mustEqual PlanetSideEmpire.TR
+                  a.app.sex mustEqual CharacterSex.Female
+                  a.app.voice mustEqual CharacterVoice.Voice5
+                  a.app.head mustEqual 16
+                  a.data match {
+                    case data: CommonFieldData =>
+                      data.faction mustEqual PlanetSideEmpire.TR
+                      data.bops mustEqual false
+                      data.alternate mustEqual false
+                      data.v1 mustEqual false
+                      data.v2.isEmpty mustEqual true
+                      data.jammered mustEqual false
+                      data.v4.isEmpty mustEqual true
+                      data.v5.isEmpty mustEqual true
+                      data.guid mustEqual ValidPlanetSideGUID(0)
+                    case _ =>
+                      ko
+                  }
+                  a.char_id mustEqual 41555698L
+                  a.exosuit mustEqual ExoSuitType.Agile
+                  a.unk5 mustEqual 0
+                  a.unk7 mustEqual 0
+                  a.unk8 mustEqual 0
+                  a.unk9 mustEqual 0
+                  a.unkA mustEqual 0
+                  b.outfit_id mustEqual 527764
+                  b.outfit_name mustEqual "****PLA****"
+                  b.outfit_logo mustEqual 1
+                  b.lfs mustEqual false
+                  b.backpack mustEqual false
+                  b.charging_pose mustEqual false
+                  b.grenade_state mustEqual GrenadeState.None
+                  b.on_zipline.isEmpty mustEqual true
+                  b.facingPitch mustEqual -5.625f
+                  b.facingYawUpper mustEqual 5.625f
+                  b.unk1 mustEqual false
+                  b.unk2 mustEqual false
+                  b.unk3 mustEqual false
+                  b.unk4 mustEqual false
+                  b.unk5 mustEqual false
+                  b.unk6 mustEqual false
+                  b.unk7 mustEqual false
+                  r mustEqual RibbonBars(
+                    MeritCommendation.AMSSupport2,
+                    MeritCommendation.HeavyAssault1,
+                    MeritCommendation.ScavengerTR1,
+                    MeritCommendation.ThreeYearTR
+                  )
+                  char.health mustEqual 100
+                  char.armor mustEqual 0
+                  char.uniform_upgrade mustEqual UniformStyle.ThirdUpgrade
+                  char.command_rank mustEqual 4
+                  char.implant_effects mustEqual Nil
+                  char.unk mustEqual 2
+                  char.cosmetics.contains(Set(Cosmetic.Earpiece, Cosmetic.Sunglasses, Cosmetic.NoHelmet)) mustEqual true
+                  pinv mustEqual List(
+                    InternalSlot(728, ValidPlanetSideGUID(3312), 0, REKData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)),3,0)),
+                    InternalSlot(132, ValidPlanetSideGUID(3665), 1, WeaponData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,None,None,ValidPlanetSideGUID(0)),0,List(
+                      InternalSlot(111,ValidPlanetSideGUID(4538),0,CommonFieldData(PlanetSideEmpire.NEUTRAL,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)))),false)
+                    ),
+                    InternalSlot(556, ValidPlanetSideGUID(3179), 2, WeaponData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,None,None,ValidPlanetSideGUID(0)),0,List(
+                      InternalSlot(28,ValidPlanetSideGUID(3221),0,CommonFieldData(PlanetSideEmpire.NEUTRAL,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)))),false)
+                    ),
+                    InternalSlot(175,ValidPlanetSideGUID(4334),4,WeaponData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,None,None,ValidPlanetSideGUID(0)),0,List(InternalSlot(540,ValidPlanetSideGUID(3833),0,CommonFieldData(PlanetSideEmpire.NEUTRAL,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)))),false))
+                  )
+                case _ =>
+                  ko
+              }
+              //1
+              val inv1 = inv(1)
+              inv1.objectClass mustEqual ObjectClass.matrix_terminalc
+              inv1.guid mustEqual PlanetSideGUID(3265)
+              inv1.parentSlot mustEqual 1
+              inv1.obj.isInstanceOf[CommonFieldData] mustEqual true
+              //2
+              val inv2 = inv(2)
+              inv2.objectClass mustEqual ObjectClass.ams_respawn_tube
+              inv2.guid mustEqual PlanetSideGUID(4346)
+              inv2.parentSlot mustEqual 2
+              inv2.obj.isInstanceOf[CommonFieldData] mustEqual true
+              //3
+              val inv3 = inv(3)
+              inv3.objectClass mustEqual ObjectClass.order_terminala
+              inv3.guid mustEqual PlanetSideGUID(4363)
+              inv3.parentSlot mustEqual 3
+              inv3.obj.isInstanceOf[CommonFieldData] mustEqual true
+              //4
+              val inv4 = inv(4)
+              inv4.objectClass mustEqual ObjectClass.order_terminalb
+              inv4.guid mustEqual PlanetSideGUID(4074)
+              inv4.parentSlot mustEqual 4
+              inv4.obj.isInstanceOf[CommonFieldData] mustEqual true
+            case _ =>
+              ko
+          }
+        case _ =>
+          ko
+      }
+    }
+
     "encode (ant)" in {
       val obj = VehicleData(
         PlacementData(3674.8438f, 2726.789f, 91.15625f, 0f, 0f, 90.0f),
@@ -165,5 +311,124 @@ class UtilityVehiclesTest extends Specification {
 
       pkt mustEqual string_ams
     }
+
+    "encode (ams, seated)" in {
+      val obj = VehicleData(
+        PlacementData(
+          Vector3(3674.8438f, 2726.789f, 91.15625f),
+          Vector3(0f, 0f, 36.5625f),
+          Some(Vector3(27.3375f, -0.78749996f, 0.1125f))
+        ),
+        CommonFieldData(PlanetSideEmpire.TR, false, false, false, None, false, Some(false), None, PlanetSideGUID(3087)),
+        unk3 = false,
+        health = 255,
+        unk4 = false,
+        no_mount_points = false,
+        DriveState.Mobile,
+        unk5 = false,
+        unk6 = false,
+        cloak = false,
+        Some(UtilityVehicleData(0)),
+        Some(InventoryData(
+          List(
+            InternalSlot(
+              ObjectClass.avatar, PlanetSideGUID(3087), 0, {
+                val a: Int => CharacterAppearanceA = CharacterAppearanceA(
+                  BasicCharacterData(
+                    "PLAmingyueTR",
+                    PlanetSideEmpire.TR,
+                    CharacterSex.Female,
+                    head = 16,
+                    CharacterVoice.Voice5
+                  ),
+                  CommonFieldData(PlanetSideEmpire.TR, false, false, false, None, false, None, None, PlanetSideGUID(0)),
+                  ExoSuitType.Agile,
+                  unk5 = 0,
+                  char_id = 41555698L,
+                  unk7 = 0,
+                  unk8 = 0,
+                  unk9 = 0,
+                  unkA = 0
+                )
+                val b: (Boolean, Int) => CharacterAppearanceB = CharacterAppearanceB(
+                  outfit_id = 527764L,
+                  outfit_name = "****PLA****",
+                  outfit_logo = 1,
+                  unk1 = false,
+                  backpack = false,
+                  unk2 = false,
+                  unk3 = false,
+                  unk4 = false,
+                  facingPitch = -5.625f,
+                  facingYawUpper = 5.625f,
+                  lfs = false,
+                  GrenadeState.None,
+                  is_cloaking = false,
+                  unk5 = false,
+                  unk6 = false,
+                  charging_pose = false,
+                  unk7 = false,
+                  on_zipline = None
+                )
+                val app: Int => CharacterAppearanceData = CharacterAppearanceData(
+                  a,
+                  b,
+                  RibbonBars(
+                    MeritCommendation.AMSSupport2,
+                    MeritCommendation.HeavyAssault1,
+                    MeritCommendation.ScavengerTR1,
+                    MeritCommendation.ThreeYearTR
+                  )
+                )
+                val char: (Boolean, Boolean) => CharacterData = CharacterData(
+                  health = 100,
+                  armor = 0,
+                  UniformStyle.ThirdUpgrade,
+                  unk = 2,
+                  command_rank = 4,
+                  implant_effects = List(),
+                  Some(Set(Cosmetic.Earpiece, Cosmetic.Sunglasses, Cosmetic.NoHelmet))
+                )
+                val inv = InventoryData(
+                  List(
+                    InternalSlot(728, ValidPlanetSideGUID(3312), 0, REKData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)),3,0)),
+                    InternalSlot(132, ValidPlanetSideGUID(3665), 1, WeaponData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,None,None,ValidPlanetSideGUID(0)),0,List(
+                      InternalSlot(111, ValidPlanetSideGUID(4538), 0, CommonFieldData(PlanetSideEmpire.NEUTRAL,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)))),false)
+                    ),
+                    InternalSlot(556, ValidPlanetSideGUID(3179), 2, WeaponData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,None,None,ValidPlanetSideGUID(0)),0,List(
+                      InternalSlot(28, ValidPlanetSideGUID(3221), 0, CommonFieldData(PlanetSideEmpire.NEUTRAL,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)))),false)
+                    ),
+                    InternalSlot(175, ValidPlanetSideGUID(4334), 4, WeaponData(CommonFieldData(PlanetSideEmpire.TR,false,false,false,None,false,None,None,ValidPlanetSideGUID(0)),0,List(InternalSlot(540,ValidPlanetSideGUID(3833),0,CommonFieldData(PlanetSideEmpire.NEUTRAL,false,false,false,None,false,Some(false),None,ValidPlanetSideGUID(0)))),false))
+                  )
+                )
+                MountableInventory.PlayerData(
+                  app,
+                  char,
+                  inv,
+                  DrawnSlot.None,
+                  MountableInventory.InitialStreamLengthToSeatEntries(hasVelocity=true, VehicleFormat.Utility)
+                )
+              }
+            ),
+            InternalSlot(
+              ObjectClass.matrix_terminalc, PlanetSideGUID(3265), 1, CommonFieldData(PlanetSideEmpire.TR)(flag = false)
+            ),
+            InternalSlot(
+              ObjectClass.ams_respawn_tube, PlanetSideGUID(4346), 2, CommonFieldData(PlanetSideEmpire.TR)(flag = false)
+            ),
+            InternalSlot(
+              ObjectClass.order_terminala, PlanetSideGUID(4363), 3, CommonFieldData(PlanetSideEmpire.TR)(flag = false)
+            ),
+            InternalSlot(
+              ObjectClass.order_terminalb, PlanetSideGUID(4074), 4, CommonFieldData(PlanetSideEmpire.TR)(flag = false)
+            )
+          )
+        ))
+      )(VehicleFormat.Utility)
+      val msg = ObjectCreateMessage(ObjectClass.ams, PlanetSideGUID(4094), obj)
+      val pkt = PacketCoding.encodePacket(msg).require.toByteVector
+
+      pkt mustEqual string_ams_seated
+    }
   }
 }
diff --git a/tools/client/src/main/scala/net/psforever/tools/client/Client.scala b/tools/client/src/main/scala/net/psforever/tools/client/Client.scala
index a8f44128d..d7f231efe 100644
--- a/tools/client/src/main/scala/net/psforever/tools/client/Client.scala
+++ b/tools/client/src/main/scala/net/psforever/tools/client/Client.scala
@@ -209,7 +209,7 @@ class Client(username: String, password: String) {
       case _ => ???
     }
     setupConnection()
-    send(ConnectToWorldRequestMessage("", state.token.get, 0, 0, 0, "", 0)).require
+    send(ConnectToWorldRequestMessage("", state.token.get, 0, 0, 0, "", 0, 0)).require
     while (true) {
       val r = waitFor[CharacterInfoMessage]().require
       if (r.finished) {