added default spawn-location

doc/RFC_XR_Fragments.md

@@ -513,6 +513,20 @@ The imported/teleported destination can be another object in the same scene-file
 
 > NOTE: hashbus links (`xrf://#foo&bar`) don't change the toplevel URL, which makes it ideal for interactions (in contrast to typical `#roomC` navigation, which benefit back/forward browser-buttons), see <a href="#hashbus">hashbus</a> for more info.
 
+> **default camera (spawn) location**: When a 3D file is loaded, it will position the user/camera at xyz: 0,0,0 OR to the location of (an object called) ''spawn''.
+
+Basically:
+
+```
+https://my.org/foo.glb
+```
+
+will load as default:
+
+```
+https://my.org/foo.glb#spawn
+```
+
 # Level3: Media Fragments 
 (!Level3: Media Fragments )