Describe encoding requirements

* Describe encoding requirements
* Change History date

Author: warsaw

peps/pep-0829.rst

@@ -215,6 +215,20 @@ continues.
    continues to the next entry point.
 
 
+Encoding
+--------
+
+``<name>.start`` files **MUST** be encoded with `utf-8-sig
+<https://docs.python.org/3.14/library/codecs.html#module-encodings.utf_8_sig>`_,
+i.e. UTF-8 with optional byte-order mark.
+
+``<name>.pth`` files **SHOULD** also be ``utf-8-sig`` encoded as well.
+Currently, decoding ``<name>.pth`` files falls back to the current locale if
+not encoded with ``utf-8-sig``, but this PEP deprecates that support for 5
+years, after which ``<name>.pth`` files **MUST** be encoded with ``utf-8-sig``
+as well.
+
+
 .. _future:
 
 Future Improvements
@@ -467,6 +481,12 @@ Open Issues
 Change History
 ==============
 
+``19-Apr-2026``
+
+* Added a description of the encoding requirements for ``<name>.start`` and
+  ``<name>.pth`` files.
+* Update the migration guidelines.
+
 `15-Apr-2026 <https://discuss.python.org/t/pep-829-structured-startup-configuration-files/106789/99>`__
 
 * During the deprecation period, warnings about ``import`` lines in