Require UAs to show manual device activation steps

Manishearth · Manishearth · commit 1b321c3445f9 · 2019-08-14T16:28:04.000-07:00
diff --git a/index.bs b/index.bs
@@ -546,7 +546,9 @@ To <dfn>initialize the session</dfn>, given |session|, |mode|, and |device|, the
   1. Set |session|'s [=XRSession/mode=] to |mode|.
   1. Set |session|'s [=XRSession/XR device=] to |device|.
   1. [=Initialize the render state=].
-  1. If no other features of the user agent have done so already, perform the necessary platform-specific steps to initialize the device's tracking and rendering capabilities.
+  1. If no other features of the user agent have done so already, perform the necessary platform-specific steps to initialize the device's tracking and rendering capabilities, including showing any necessary instructions to the user.
+
+Note: Some devices require additional user instructions for activation, for example going into immersive mode on a phone-based headset device requires inserting the phone into the headset, and doing so on a desktop browser connected to an external headset requires wearing the headset. It is the responsibility of the user agent &mdash; not the author &mdash; to ensure any such instructions are shown.
 
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