docstring

Author: d-v-b

src/zarr/core/array.py

@@ -152,12 +152,14 @@ class DefaultFillValue:
     """
     Sentinel class to indicate that the default fill value should be used.
 
-    This class exists because the normal values used to convey "defaultness" 
-    like ``None`` or ``"auto"` do not work for the fill value parameter of a Zarr array. 
-    ``None`` is a valid fill value for Zarr V2 (resulting in ``"fill_value: null"`` in array metadata). 
-    A string like ``"auto"`` is a valid fill value for an array with a string data type. 
-    But an instance of this class lies outside the space of valid fill values, which makes it 
-    suitable for expressing that the default fill value should be used.
+    This class exists because conventional values used to convey "defaultness" like ``None`` or
+    ``"auto"` are ambiguous when specifying the fill value parameter of a Zarr array.
+    The value ``None`` is ambiguous because it is a valid fill value for Zarr V2
+    (resulting in ``"fill_value": null`` in array metadata).
+    A string like ``"auto"`` is ambiguous because such a string is a valid fill value for an array
+    with a string data type.
+    An instance of this class lies outside the space of valid fill values, which means it can
+    umambiguously express that the default fill value should be used.
     """