PEP 809: Updates from discussion

Author: zooba

peps/pep-0809.rst

@@ -157,6 +157,18 @@ are not permitted. That is, the APIs to detect whether a particular behaviour is
 expected on the current Python release must have been available on all earlier
 releases that support the ABI.
 
+Accidental changes that occur in releases should be reverted as soon as
+discovered, ideally without breaking regular compatibility rules. However, it is
+better to have `3.x.1` fix a Stable ABI issue introduced in `3.x.0` rather than
+to leave it present until `3.y.0`.
+
+Historically, we have used clever C preprocessor constructs to try and preserve
+both source and binary-level compatibility, for example, by selecting macro or
+inline functions automatically. Under this new scheme, these should be avoided
+in favour of a much more direct relationship between the documented C API and
+the shape of the ABI. Changes can be scheduled for the next version of the ABI
+if they are important enough to be made.
+
 
 Opaque PyObject
 ---------------