Issue #1789: clarify that the 'size' column in struct docs refers to standard size.
diff --git a/Doc/library/struct.rst b/Doc/library/struct.rst
index f76e4a1..b5fd432 100644
--- a/Doc/library/struct.rst
+++ b/Doc/library/struct.rst
@@ -156,7 +156,11 @@
^^^^^^^^^^^^^^^^^
Format characters have the following meaning; the conversion between C and
-Python values should be obvious given their types:
+Python values should be obvious given their types. The 'Standard size' column
+refers to the size of the packed value in bytes when using standard size; that
+is, when the format string starts with one of ``'<'``, ``'>'``, ``'!'`` or
+``'='``. When using native size, the size of the packed value is
+platform-dependent.
+--------+-------------------------+--------------------+----------------+------------+
| Format | C Type | Python type | Standard size | Notes |