doc

Updating NetworkObject documentation and in-scene placed documentation.

Author: NoelStephensUnity

com.unity.netcode.gameobjects/Documentation~/basics/scenemanagement/inscene-placed-networkobjects.md

@@ -184,9 +184,13 @@ public class MyInSceneNetworkObjectBehaviour : NetworkBehaviour
 > [!NOTE]
 > You only need to enable the NetworkObject on the server-side to be able to respawn it. Netcode for GameObjects only enables a disabled in-scene placed NetworkObject on the client-side if the server-side spawns it. This **does not** apply to dynamically spawned `NetworkObjects`. Refer to [the object pooling page](../../advanced-topics/object-pooling.md) for an example of recycling dynamically spawned NetworkObjects.
 
+### Pre-disabled in-scene placed NetworkObjects
+
+If you want to always have an in-scene placed NetworkObject start off as disabled and then spawn it at a later time, you only need to set its GameObject to inactive in the editor while the respective scene is open. Once you have started a networked session, you can re-enable it and then spawn it any time.
+
 ### Setting an in-scene placed NetworkObject to a despawned state when instantiating
 
-Since in-scene placed NetworkObjects are automatically spawned when their respective scene has finished loading during a network session, you might run into the scenario where you want it to start in a despawned state until a certain condition has been met. To do this, you need to add some additional code in the `OnNetworkSpawn` part of your NetworkBehaviour component:
+If you want to programmatically disable an in-scene placed NetworkObject you can add some additional code in the `OnNetworkSpawn` part of a NetworkBehaviour component:
 
 ```csharp
 using UnityEngine;

com.unity.netcode.gameobjects/Documentation~/components/core/networkobject.md

@@ -19,6 +19,23 @@ When spawning a NetworkObject, the `NetworkObject.GlobalObjectIdHash` value init
 
 You can use [NetworkBehaviours](networkbehaviour.md) to add your own custom Netcode logic to the associated NetworkObject.
 
+### What is a valid NetworkObject?
+
+There are basically two categories of NetworkObjects:
+
+- Dynamically instantiated network prefabs.
+  - Requirements:
+    - It must be a valid [network prefab](./networkobject.md#network-prefabs) created within the editor.
+    - It must be registered within a network prefab list that is assigned to your NetworkManager.
+- [In-scene placed](../../basics/scenemanagement/inscene-placed-networkobjects.md):
+  - Requirements:
+    - It can be a valid network prefab instance within a scene.
+    - It can be a GameObject with a `NetworkObject` component created within the scene while in the editor.
+
+### What is an invalid NetworkObject?
+
+Any GameObjects that have `NetworkObject` components added to them during runtime is **not supported** and will result in the NetworkObject's `GlobalObjectIdHash` being zero which would eventually result in synchronization issues. In the event you make this mistake, a warning message will be logged and the NetworkObject will not get spawned.
+
 ### Component order
 
 The order of components on a networked GameObject matters. When adding netcode components to a GameObject, ensure that the NetworkObject component is ordered before any NetworkBehaviour components.