RST401 now RST309 (downgraded in docutils v0.22)

Author: peterjc

README.rst

@@ -126,6 +126,7 @@ RST305 Undefined substitution referenced: "XXX".
 RST306 Unknown target name: "XXX".
 RST307 Error in "XXX" directive:
 RST308 Duplicate target name, cannot be used as a unique reference: "XXX".
+RST309 Unexpected section title. *(replaced RST401 in docutils v0.22)*
 RST399 Previously unseen major error, not yet assigned a unique code.
 ====== =======================================================================
 
@@ -134,7 +135,7 @@ Severe or critical error codes:
 ====== =======================================================================
 Code   Description
 ------ -----------------------------------------------------------------------
-RST401 Unexpected section title.
+RST401 Unexpected section title. *(downgraded to error, see RST309)*
 RST499 Previously unseen severe error, not yet assigned a unique code.
 ====== =======================================================================
 
@@ -249,6 +250,7 @@ Version Released   Changes
 ------- ---------- -----------------------------------------------------------
 v0.4.0  *Pending*  - Tested with docutils v0.22.2
                    - Adds `RST308` for duplicated target names.
+                   - Adds `RST309` replacing `RST401` (downgraded severity).
                    - Requires Python 3.9 or later.
 v0.3.1  2025-04-29 - Adds ``RST220`` for redefined anonymous links.
                    - Requires Python 3.8 or later (no code changes).

flake8_rst_docstrings.py

@@ -82,10 +82,15 @@
     'Error in "*" directive:': 7,
     # e.g. Duplicate target name, cannot be used as a unique reference: "python".
     'Duplicate target name, cannot be used as a unique reference: "*".': 8,
+    # This was RST401 prior to docutils v0.22:
+    "Unexpected section title.": 9,
 }
 
 # Level 4 - severe
-code_mapping_severe = {"Unexpected section title.": 1}
+code_mapping_severe = {
+    # See RST308 as of docutils v0.22:
+    "Unexpected section title.": 1,
+}
 
 code_mappings_by_level = {
     1: code_mapping_info,

tests/RST401/sub_title.py tests/RST309/sub_title.pytests/RST401/sub_title.py renamed to tests/RST309/sub_title.py

@@ -2,8 +2,8 @@
 
 This should fail validation:
 
-    $ flake8 --select RST RST401/sub_title.py
-    RST401/sub_title.py:20:1: RST401 Unexpected section title.
+    $ flake8 --select RST RST309/sub_title.py
+    RST309/sub_title.py:20:1: RST309 Unexpected section title.
 
 See below.
 """