[doc] struct: update note about network byte order form to be more helpful (GH-22201)
Update the sentence to provide some context on why network byte order is defined as big endian.
diff --git a/Doc/library/struct.rst b/Doc/library/struct.rst
index 856b6da..eccba20 100644
--- a/Doc/library/struct.rst
+++ b/Doc/library/struct.rst
@@ -159,8 +159,8 @@
Note the difference between ``'@'`` and ``'='``: both use native byte order, but
the size and alignment of the latter is standardized.
-The form ``'!'`` is available for those poor souls who claim they can't remember
-whether network byte order is big-endian or little-endian.
+The form ``'!'`` represents the network byte order which is always big-endian
+as defined in `IETF RFC 1700 <IETF RFC 1700_>`_.
There is no way to indicate non-native byte order (force byte-swapping); use the
appropriate choice of ``'<'`` or ``'>'``.
@@ -467,3 +467,5 @@
.. _half precision format: https://en.wikipedia.org/wiki/Half-precision_floating-point_format
.. _ieee 754 standard: https://en.wikipedia.org/wiki/IEEE_floating_point#IEEE_754-2008
+
+.. _IETF RFC 1700: https://tools.ietf.org/html/rfc1700