diff --git a/bin/OpenSimDefaults.ini b/bin/OpenSimDefaults.ini
index 8cde201a56..c11a14b882 100644
--- a/bin/OpenSimDefaults.ini
+++ b/bin/OpenSimDefaults.ini
@@ -1489,10 +1489,22 @@
     ; Worst case is twisted tube, 0.5+sqrt(1.25)
     PrimBoundingBoxSafetyCoefficientZ = 1.618034
 
-    ; Use llCastRay V3 if true
-    ; Gives better accuracy and can be faster on some servers, but slower on others,
-    ; compared to previous version of llCastRay
-    ; Generates geometry meshes and can therefore use much system resources
+    ; Use llCastRay V3 if true.
+    ; Implements llCastRay similar but not identical to Second Life.
+    ; See http://wiki.secondlife.com/wiki/LlCastRay .
+    ; NEW
+    ; Meshes prims for good accuracy in ray hit detection,
+    ; handling basic and tortured prims, sculpts and meshes.
+    ; Uses ellipsoid, correctly sized avatar capsules.
+    ; Handles complex terrain, multi-prim objects and seated avatars.
+    ; Implements throttling and the status codes
+    ; RCERR_UNKNOWN and RCERR_CAST_TIME_EXCEEDED,
+    ; so LSL scripts need to handle these responses and RCERR_SIM_PERF_LOW.
+    ; WARNING
+    ; Can be faster on some servers and scenes, but slower on others,
+    ; compared to previous version of llCastRay in OpenSimulator.
+    ; Is in most cases considerably slower than llCastRay in Second Life.
+    ; Generates geometry meshes and can therefore use much system resources.
     UseLlCastRayV3 = false
 
     ; Accepted calculation precision error in calculations in llCastRay V3