diff --git a/API-Robot.md b/API-Robot.md
index 5f168ce..5eb3e09 100644
--- a/API-Robot.md
+++ b/API-Robot.md
@@ -20,7 +20,8 @@ This API abstracts the computer component of a robot to allow more intuitive int
 - `robot.compareTo(slot: number): boolean`  
   Compares the item in the currently selected slot to the item in the specified slot. Returns `true` if the *items* are equal (i.e. the stack size does not matter), `false` otherwise.
 - `robot.transferTo(slot: number[, count: number]): boolean`  
-  Moves items from the selected slot into the specified slot. If count is specified only moves up to this number of items. Returns `true` if one or more items were moved (but not necessarily all of them!), `false` if no items could be moved.
+  Moves items from the selected slot into the specified slot. If count is specified only moves up to this number of items. Returns `true` if one or more items were moved (but not necessarily all of them!), `false` if no items could be moved.  
+  Note that if the target slot is *not* empty, and the number of items to move is unspecified or larger or equal to the number items in the selected slot, this will result in a swap.
 - `robot.compare(): boolean`  
   Compares the item in the currently selected inventory slot to the block in front of the robot. Returns `true` if the block is equivalent to the item at the selected slot, `false` otherwise.
 - `robot.compareUp(): boolean`