Decoupling instance handling from model

docs-gen/content/rule_set/instances.md

@@ -48,8 +48,9 @@ with two axles and two rows of seats. For other vehicles, see [recommendations o
 
 Typical naming conventions used in VSS standard catalog include:
 
-* When instances are defined by a range, e.g., `Position[m,n]`, VSS standard catalog uses `1` as start index for the first instance.
+* When instances are defined by a range, e.g., `Index[m,n]`, VSS standard catalog uses `1` as start index for the first instance.
 * The instance definition `Row[n,m]`, e.g., `Row[1,2]`, is used to indicate that there are multiple rows of the entity. Rows are counted from the front of the vehicle.
+* The instance definition `Position[n,m]`, e.g., `Position[1,3]`, is used to indicate that there are multiple positions of the entity (for a specific row). Posistions are counted from the left of the vehicle.
 * For items located on either left or right side of the vehicle VSS standard catalog uses two different conventions:
   * In some cases instances are defined relative to driver position, e.g., `["DriverSide", "PassengerSide"]`.
   * In other cases instances are defined based on physical position, e.g., `["Left","Right"]`.

spec/Cabin/Cabin.vspec

@@ -144,9 +144,6 @@ IsWindowChildLockEngaged:
 
 Seat:
   type: branch
-  instances:
-    - Row[1,2]
-    - ["DriverSide","Middle","PassengerSide"]
   description: All seats.
 #include Seat.vspec Seat
 

spec/Chassis/Chassis.vspec

@@ -22,8 +22,6 @@ Wheelbase:
 # Axle definition
 #
 Axle:
-  instances:
-    - Row[1,2]
   type: branch
   description: Axle signals
 
@@ -125,7 +123,6 @@ Axle.Torque:
 # Wheels on Axles
 #
 Axle.Wheel:
-  instances: ["Left","Right"]
   type: branch
   description: Wheel signals for axle
 

spec/default_instances.vspec

@@ -0,0 +1,33 @@
+# Copyright (c) 2026 Contributors to COVESA
+#
+# This program and the accompanying materials are made available under the
+# terms of the Mozilla Public License 2.0 which is available at
+# https://www.mozilla.org/en-US/MPL/2.0/
+#
+# SPDX-License-Identifier: MPL-2.0
+
+# The default instance file shall reflect typical setup for a "normal" passenger car
+# The instance pattern in this file is non-normative, but shall be seen as a recommendation
+
+# Instance recommendations
+
+# If using Row[x,y]
+
+
+
+Vehicle.Chassis.Axle:
+  type: branch
+  instances:
+    - Row[1,2]
+
+
+Vehicle.Chassis.Axle.Wheel:
+  type: branch
+  instances: ["Left","Right"]
+
+
+Vehicle.Cabin.Seat:
+  type: branch
+  instances:
+    - Row[1,2]
+    - ["DriverSide","Middle","PassengerSide"]