diff --git a/torchvision/ops/boxes.py b/torchvision/ops/boxes.py
index <HASH>..<HASH> 100644
--- a/torchvision/ops/boxes.py
+++ b/torchvision/ops/boxes.py
@@ -14,6 +14,11 @@ def nms(boxes, scores, iou_threshold):
     IoU greater than iou_threshold with another (higher scoring)
     box.
 
+    If multiple boxes have the exact same score and satisfy the IoU 
+    criterion with respect to a reference box, the selected box is 
+    not guaranteed to be the same between CPU and GPU. This is similar 
+    to the behavior of argsort in PyTorch when repeated values are present.
+
     Parameters
     ----------
     boxes : Tensor[N, 4])
Improve documentation for NMS (#<I>)

* Improve documentation for NMS



* update nms doc for special case