#10742: document readonly attribute of memoryviews.
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index db2c958..be0c8d5 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -2433,6 +2433,10 @@
A tuple of integers the length of :attr:`ndim` giving the size in bytes to
access each element for each dimension of the array.
+ .. attribute:: readonly
+
+ A bool indicating whether the memory is read only.
+
.. memoryview.suboffsets isn't documented because it only seems useful for C