diff --git a/AGENTS.md b/AGENTS.md
index 24c297de..92304477 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -172,14 +172,17 @@ uv run sphinx-build -b html docs dist/docs
 #    covers those is _CORPUS_CLAIMS, which records what every rule claims
 #    -- its regex's corpus reach, its roles, and which names -- and so
 #    needs no notion of how a copy is spelled.
-#    FOUR rosters are keyed by FILENAME and checked by EQUALITY, so a new
+#    SIX rosters are keyed by FILENAME and checked by EQUALITY, so a new
 #    ledger must be enrolled in every one of them on the day it lands, even
-#    empty -- each fails loudly and names itself, but that is four separate
-#    red runs if you add them one at a time. Three sit in the test module
-#    and one in tools/differential/compare.py; a fifth, compare.py's
-#    _RECORDED_DIFFS, is enrolled transitively, since the guard holds
-#    set(_RECORDED_DIFFS) == set(_CROSS_RULE_WINNERS). Two more are keyed
-#    by rule CONTENT and apply only where such a rule exists.
+#    empty -- each fails loudly and names itself, but that is six separate
+#    red runs if you add them one at a time. Four sit in the test module
+#    and two in tools/differential/compare.py. Faster than reading this
+#    list: create the ledger, move DEFAULT_BASELINE, and run
+#    tests/v2/test_ledger_guards.py once -- every roster still missing the
+#    file fails by name. (Opening the 2.4 cycle found _ORDER_EXEMPTION_EFFECT
+#    that way; it landed with f478fb0 after this list was last written.)
+#    Two more are keyed by rule CONTENT and apply only where such a rule
+#    exists.
 #    Required, by filename:
 #      - _SPAN_BEARING_RULES: add the filename, mapped to the set of issue
 #        tags whose rules carry a script-span class (empty set if none).
@@ -201,6 +204,11 @@ uv run sphinx-build -b html docs dist/docs
 #        run itself refuses, pre-worker, a ledger missing from either
 #        shape roster -- an empty section is a statement, a missing one is
 #        nobody having looked -- so the guard and the run agree on it.
+#      - _ORDER_EXEMPTION_EFFECT: add the filename mapped to [] while the
+#        ledger has no order-decided contest. It is the recorded negative
+#        control for precedes_narrower -- every contest measured with
+#        exemptions ignored -- so a row appears when two rules land that
+#        file order alone arbitrates, whether or not one declares it.
 #    Conditional, by rule content:
 #      - _HONORIFIC_SOURCES: if the ledger has a CJK honorific rule, add a
 #        substring of its issue (keyed that way, not by tag) mapped to the
diff --git a/docs/release_log.rst b/docs/release_log.rst
index e15e2f1a..63f70bc4 100644
--- a/docs/release_log.rst
+++ b/docs/release_log.rst
@@ -1,5 +1,9 @@
 Release Log
 ===========
+* 2.4.0 - Unreleased
+
+    nameparser 2.4 is under development.
+
 * 2.3.0 - September 12, 2026
 
     nameparser 2.3 is parsing fixes and new honorific vocabulary;
diff --git a/nameparser/_version.py b/nameparser/_version.py
index d7df1fcc..7a45feb7 100644
--- a/nameparser/_version.py
+++ b/nameparser/_version.py
@@ -4,16 +4,16 @@
 #:
 #: Bumped when a cycle OPENS, not when it ships, so the tree says what
 #: it is building. Note the cost of the tuple being purely numeric: it
-#: cannot carry the dev marker, so `VERSION >= (2, 2, 0)` is already
-#: true here while 2.2.0 is unreleased. Compare `__version__` instead
+#: cannot carry the dev marker, so `VERSION >= (2, 4, 0)` is already
+#: true here while 2.4.0 is unreleased. Compare `__version__` instead
 #: where that distinction matters.
-VERSION = (2, 3, 0)
+VERSION = (2, 4, 0)
 #: PEP 440 pre-release/dev segment appended to the numeric version, or
 #: "" for a final release. Joined WITHOUT a dot ("2.0.0rc1", not
 #: "2.0.0.rc1"); setuptools reads __version__ as the package version.
 #:
 #: "dev" through the cycle, cleared at release. It normalizes to
-#: 2.3.0.dev0, which sorts above 2.2.0 and BELOW 2.3.0, so an install
+#: 2.4.0.dev0, which sorts above 2.3.0 and BELOW 2.4.0, so an install
 #: from master can never masquerade as the release it precedes.
-PRE_RELEASE = ""
+PRE_RELEASE = "dev"
 __version__ = ".".join(map(str, VERSION)) + PRE_RELEASE
diff --git a/tests/v2/test_ledger_guards.py b/tests/v2/test_ledger_guards.py
index ccff26f9..9a24336a 100644
--- a/tests/v2/test_ledger_guards.py
+++ b/tests/v2/test_ledger_guards.py
@@ -354,9 +354,8 @@ def test_script_ranges_membership_is_decided() -> None:
         "fix(#298)",                        # the 间隔号 lookahead
     }),
     "expected_since_2.1.0.toml": frozenset(),   # 2.2 cycle: no span-bearing rule
-    # open cycle: its one rule, fix(#462), is a Latin letter shape and
-    # copies no script range
-    "expected_since_2.2.0.toml": frozenset(),
+    "expected_since_2.2.0.toml": frozenset(),   # 2.3 cycle: no span-bearing rule
+    "expected_since_2.3.0.toml": frozenset(),   # open cycle, no rules yet
 }
 
 #: The leading `fix(...)`/`feat(...)` tag of a rule's `issue`, which is
@@ -3367,6 +3366,7 @@ def _claim(rule: dict) -> _Claim:
             _Claim(17, ('_ambiguities', 'family', 'given', 'middle',
                         'suffix', 'title'), "ef4a7afe791a", None),
     },
+    "expected_since_2.3.0.toml": {},   # open cycle, no rules yet
 }
 
 
@@ -3467,8 +3467,9 @@ def test_every_rule_claims_the_recorded_share_of_the_corpus() -> None:
 #: default-order only, the blind spot `orders` (#468) opened. One copy
 #: of each fact, since two means one of them goes quietly stale.
 _CROSS_RULE_WINNERS: dict[str, dict[str, str]] = {
-    # open cycle: one rule, so nothing for a second one to contest
     "expected_since_2.2.0.toml": {},
+    # open cycle: no rules, so no contest
+    "expected_since_2.3.0.toml": {},
     "expected_since_1.4.0.toml": {
         # Spelled out since #508: the bare `fix(comma-family)` this row
         # carried is a prefix of THREE rules in this ledger (measured
@@ -4978,6 +4979,7 @@ def test_a_rule_reaching_no_corpus_name_says_why_it_is_kept() -> None:
     ],
     "expected_since_2.1.0.toml": [],
     "expected_since_2.2.0.toml": [],
+    "expected_since_2.3.0.toml": [],   # open cycle, no rules yet
 }
 
 
diff --git a/tools/differential/compare.py b/tools/differential/compare.py
index 549a344d..9c2e62fc 100644
--- a/tools/differential/compare.py
+++ b/tools/differential/compare.py
@@ -31,7 +31,7 @@
 FIELDS = ("title", "first", "middle", "last", "suffix", "nickname",
           "maiden")
 
-DEFAULT_BASELINE = "2.2.0"
+DEFAULT_BASELINE = "2.3.0"
 REPO_ROOT = HERE.parents[1]
 #: The v2 API's names for the same seven roles FIELDS names in v1
 #: vocabulary. Both are compared from baseline 2.0 on.
@@ -1746,8 +1746,9 @@ class _ShapeMismatch(NamedTuple):
 #: every run. 'Nguyen, Van' is classified by nothing only because it
 #: diffs from nothing.
 _RECORDED_DIFFS: dict[str, dict[str, tuple[str, ...]]] = {
-    # open cycle: one rule, so nothing for a second one to contest
     "expected_since_2.2.0.toml": {},
+    # open cycle: no rules, so nothing for a second one to contest
+    "expected_since_2.3.0.toml": {},
     "expected_since_1.4.0.toml": {
         "Andrews, M.D.": ("given", "suffix"),
         "田中, 太郎さん": ("given", "suffix"),
@@ -2151,6 +2152,7 @@ class _ShapeMismatch(NamedTuple):
         "Lala Lajpat Rai": ("family", "middle", "suffix"),
         "Smith, John E, III, Jr": ("_initials",),
     },
+    "expected_since_2.3.0.toml": {},   # open cycle, no watched name yet
 }
 
 
diff --git a/tools/differential/expected_since_2.3.0.toml b/tools/differential/expected_since_2.3.0.toml
new file mode 100644
index 00000000..952867fa
--- /dev/null
+++ b/tools/differential/expected_since_2.3.0.toml
@@ -0,0 +1,34 @@
+# Ledger for baseline 2.3.0 -- what changes for a user upgrading from
+# the previous minor. Same rule grammar as the other ledgers: `issue`,
+# `name_regex` and `fields` are every one of them required. Neither
+# narrowing key may stand on its own -- #451 banned a rule with
+# `fields` and no regex, #456 banned the reverse -- so a rule here
+# narrows by name AND by role, never by just one.
+#
+# Opened empty the day 2.3.0 shipped (AGENTS.md release step 8), and it
+# is opened before it has anything to say because DEFAULT_BASELINE and
+# the ledger are coupled: _allowlist_for treats a missing file as a
+# hard error, on the reasoning that an absent ledger classifies nothing
+# and would make every diff report as unexplained. So the baseline
+# could not advance to 2.3.0 without this file.
+#
+# Do not copy rules across from expected_since_2.2.0.toml: that ledger
+# classifies what 2.3 changed on top of 2.2, and a rule copied without
+# checking either over-matches -- hiding a real 2.4 regression behind a
+# 2.3-era label -- or never fires at all. Where a 2.4 change is visible
+# from several baselines the rule may legitimately appear in more than
+# one file, but each copy is checked against its own run rather than
+# assumed.
+#
+# tests/v2/test_differential.py permits exactly one empty ledger, the
+# one DEFAULT_BASELINE names -- which is this file.
+#
+# tests/v2/test_ledger_guards.py and tools/differential/compare.py
+# enroll this file, empty, in every roster keyed by ledger filename
+# (AGENTS.md release step 8 lists them). The first rule that copies a
+# script range, a CJK honorific or a Latin vocabulary has to be
+# recorded in its roster or the sweep fails.
+#
+# There is deliberately no `change = []` line. TOML forbids appending a
+# [[change]] table to a statically defined array, so that line would
+# block the first entry.