diff --git a/conformance/results/mypy/namedtuples_define_class.toml b/conformance/results/mypy/namedtuples_define_class.toml
index adf590b4..575c5c0c 100644
--- a/conformance/results/mypy/namedtuples_define_class.toml
+++ b/conformance/results/mypy/namedtuples_define_class.toml
@@ -11,11 +11,19 @@ namedtuples_define_class.py:46: error: Argument 2 to "Point" has incompatible ty
 namedtuples_define_class.py:47: error: Argument "units" to "Point" has incompatible type "int"; expected "str"  [arg-type]
 namedtuples_define_class.py:48: error: Too many arguments for "Point"  [call-arg]
 namedtuples_define_class.py:49: error: Unexpected keyword argument "other" for "Point"  [call-arg]
-namedtuples_define_class.py:59: error: Non-default NamedTuple fields cannot follow default fields  [misc]
-namedtuples_define_class.py:98: error: Argument 2 to "Property" has incompatible type "float"; expected "str"  [arg-type]
-namedtuples_define_class.py:105: error: NamedTuple should be a single base  [misc]
+namedtuples_define_class.py:59: error: Invalid statement in NamedTuple definition; expected "field_name: field_type [= default]"  [misc]
+namedtuples_define_class.py:65: error: Missing positional argument "units" in call to "Point2"  [call-arg]
+namedtuples_define_class.py:67: error: Too many values to unpack (2 expected, 3 provided)  [misc]
+namedtuples_define_class.py:76: error: NamedTuple field name cannot start with an underscore: _y  [misc]
+namedtuples_define_class.py:86: error: Non-default NamedTuple fields cannot follow default fields  [misc]
+namedtuples_define_class.py:125: error: Argument 2 to "Property" has incompatible type "float"; expected "str"  [arg-type]
+namedtuples_define_class.py:132: error: NamedTuple should be a single base  [misc]
 """
 conformance_automated = "Fail"
 errors_diff = """
-Line 79: Expected 1 errors
+Line 69: Expected 1 errors
+Line 106: Expected 1 errors
+Line 59: Unexpected errors ['namedtuples_define_class.py:59: error: Invalid statement in NamedTuple definition; expected "field_name: field_type [= default]"  [misc]']
+Line 65: Unexpected errors ['namedtuples_define_class.py:65: error: Missing positional argument "units" in call to "Point2"  [call-arg]']
+Line 67: Unexpected errors ['namedtuples_define_class.py:67: error: Too many values to unpack (2 expected, 3 provided)  [misc]']
 """
diff --git a/conformance/results/mypy/namedtuples_define_functional.toml b/conformance/results/mypy/namedtuples_define_functional.toml
index 151e6588..19158d3d 100644
--- a/conformance/results/mypy/namedtuples_define_functional.toml
+++ b/conformance/results/mypy/namedtuples_define_functional.toml
@@ -11,8 +11,15 @@ namedtuples_define_functional.py:43: error: Argument "x" to "Point6" has incompa
 namedtuples_define_functional.py:52: error: "namedtuple()" has duplicate field name "a"  [misc]
 namedtuples_define_functional.py:53: error: "namedtuple()" field name "def" is a keyword  [misc]
 namedtuples_define_functional.py:54: error: "namedtuple()" field name "def" is a keyword  [misc]
-namedtuples_define_functional.py:66: error: Missing positional argument "a" in call to "NT5"  [call-arg]
+namedtuples_define_functional.py:55: error: "namedtuple()" field name "_d" starts with an underscore  [misc]
+namedtuples_define_functional.py:66: error: Name "NT5" already defined on line 57  [no-redef]
+namedtuples_define_functional.py:67: error: Missing positional argument "_1" in call to "NT5"  [call-arg]
+namedtuples_define_functional.py:68: error: Too many arguments for "NT5"  [call-arg]
+namedtuples_define_functional.py:69: error: Missing positional arguments "abc", "_1" in call to "NT5"  [call-arg]
 """
-conformance_automated = "Pass"
+conformance_automated = "Fail"
 errors_diff = """
+Line 66: Unexpected errors ['namedtuples_define_functional.py:66: error: Name "NT5" already defined on line 57  [no-redef]']
+Line 67: Unexpected errors ['namedtuples_define_functional.py:67: error: Missing positional argument "_1" in call to "NT5"  [call-arg]']
+Line 68: Unexpected errors ['namedtuples_define_functional.py:68: error: Too many arguments for "NT5"  [call-arg]']
 """
diff --git a/conformance/results/mypy/version.toml b/conformance/results/mypy/version.toml
index 6bd36c63..869e8bf2 100644
--- a/conformance/results/mypy/version.toml
+++ b/conformance/results/mypy/version.toml
@@ -1,2 +1,2 @@
 version = "mypy 1.15.0"
-test_duration = 2.1
+test_duration = 2.0
diff --git a/conformance/results/pyre/namedtuples_define_class.toml b/conformance/results/pyre/namedtuples_define_class.toml
index 3ce86df7..d60d70ca 100644
--- a/conformance/results/pyre/namedtuples_define_class.toml
+++ b/conformance/results/pyre/namedtuples_define_class.toml
@@ -16,11 +16,15 @@ namedtuples_define_class.py:46:14 Incompatible parameter type [6]: In call `Poin
 namedtuples_define_class.py:47:17 Incompatible parameter type [6]: In call `Point.__init__`, for argument `units`, expected `str` but got `int`.
 namedtuples_define_class.py:48:5 Too many arguments [19]: Call `Point.__init__` expects 3 positional arguments, 4 were provided.
 namedtuples_define_class.py:49:6 Unexpected keyword [28]: Unexpected keyword argument `other` to call `Point.__init__`.
-namedtuples_define_class.py:59:4 Missing named tuple default [74]: Named tuple field without default value may not be preceded by a field with default value.
-namedtuples_define_class.py:79:4 Invalid assignment [41]: Cannot reassign final attribute `x`.
-namedtuples_define_class.py:98:18 Incompatible parameter type [6]: In call `Property.__init__`, for 2nd positional argument, expected `str` but got `float`.
-namedtuples_define_class.py:105:23 Invalid inheritance [39]: If NamedTuple is included as a base class, the class may not extend anything else besides Generic.
+namedtuples_define_class.py:67:0 Unable to unpack [23]: Unable to unpack 3 values, 2 were expected.
+namedtuples_define_class.py:86:4 Missing named tuple default [74]: Named tuple field without default value may not be preceded by a field with default value.
+namedtuples_define_class.py:106:4 Invalid assignment [41]: Cannot reassign final attribute `x`.
+namedtuples_define_class.py:125:18 Incompatible parameter type [6]: In call `Property.__init__`, for 2nd positional argument, expected `str` but got `float`.
+namedtuples_define_class.py:132:23 Invalid inheritance [39]: If NamedTuple is included as a base class, the class may not extend anything else besides Generic.
 """
-conformance_automated = "Pass"
+conformance_automated = "Fail"
 errors_diff = """
+Line 69: Expected 1 errors
+Line 76: Expected 1 errors
+Line 67: Unexpected errors ['namedtuples_define_class.py:67:0 Unable to unpack [23]: Unable to unpack 3 values, 2 were expected.']
 """
diff --git a/conformance/results/pyre/namedtuples_define_functional.toml b/conformance/results/pyre/namedtuples_define_functional.toml
index dc132443..62b05c17 100644
--- a/conformance/results/pyre/namedtuples_define_functional.toml
+++ b/conformance/results/pyre/namedtuples_define_functional.toml
@@ -12,8 +12,12 @@ namedtuples_define_functional.py:42:17 Incompatible parameter type [6]: In call
 namedtuples_define_functional.py:43:14 Incompatible parameter type [6]: In call `Point6.__init__`, for argument `x`, expected `int` but got `float`.
 namedtuples_define_functional.py:52:0 Duplicate parameter [65]: Duplicate parameter name `a`.
 namedtuples_define_functional.py:52:0 Duplicate parameter [65]: Duplicate parameter name `a`.
-namedtuples_define_functional.py:66:0 Missing argument [20]: Call `NT5.__init__` expects argument `a`.
+namedtuples_define_functional.py:58:0 Unexpected keyword [28]: Unexpected keyword argument `abc` to call `NT5.__init__`.
+namedtuples_define_functional.py:60:0 Unexpected keyword [28]: Unexpected keyword argument `_1` to call `NT6.__init__`.
+namedtuples_define_functional.py:69:0 Missing argument [20]: Call `NT5.__init__` expects argument `a`.
 """
-conformance_automated = "Pass"
+conformance_automated = "Fail"
 errors_diff = """
+Line 58: Unexpected errors ['namedtuples_define_functional.py:58:0 Unexpected keyword [28]: Unexpected keyword argument `abc` to call `NT5.__init__`.']
+Line 60: Unexpected errors ['namedtuples_define_functional.py:60:0 Unexpected keyword [28]: Unexpected keyword argument `_1` to call `NT6.__init__`.']
 """
diff --git a/conformance/results/pyre/version.toml b/conformance/results/pyre/version.toml
index c60d2044..94de3055 100644
--- a/conformance/results/pyre/version.toml
+++ b/conformance/results/pyre/version.toml
@@ -1,2 +1,2 @@
 version = "pyre 0.9.23"
-test_duration = 3.9
+test_duration = 7.3
diff --git a/conformance/results/pyright/namedtuples_define_class.toml b/conformance/results/pyright/namedtuples_define_class.toml
index 19f9aadc..42aabbf3 100644
--- a/conformance/results/pyright/namedtuples_define_class.toml
+++ b/conformance/results/pyright/namedtuples_define_class.toml
@@ -10,12 +10,14 @@ namedtuples_define_class.py:47:24 - error: Argument of type "Literal[3]" cannot
   "Literal[3]" is not assignable to "str" (reportArgumentType)
 namedtuples_define_class.py:48:22 - error: Expected 3 positional arguments (reportCallIssue)
 namedtuples_define_class.py:49:23 - error: No parameter named "other" (reportCallIssue)
-namedtuples_define_class.py:59:5 - error: Fields without default values cannot appear after fields with default values (reportGeneralTypeIssues)
-namedtuples_define_class.py:79:5 - error: Cannot override "x" because parent class "Point" is a named tuple (reportIncompatibleVariableOverride)
-namedtuples_define_class.py:98:19 - error: Argument of type "float" cannot be assigned to parameter "value" of type "str" in function "__new__"
+namedtuples_define_class.py:69:20 - error: Expected 2 positional arguments (reportCallIssue)
+namedtuples_define_class.py:86:5 - error: Fields without default values cannot appear after fields with default values (reportGeneralTypeIssues)
+namedtuples_define_class.py:106:5 - error: Cannot override "x" because parent class "Point" is a named tuple (reportIncompatibleVariableOverride)
+namedtuples_define_class.py:125:19 - error: Argument of type "float" cannot be assigned to parameter "value" of type "str" in function "__new__"
   "float" is not assignable to "str" (reportArgumentType)
-namedtuples_define_class.py:105:7 - error: Multiple inheritance with NamedTuple is not supported (reportGeneralTypeIssues)
+namedtuples_define_class.py:132:7 - error: Multiple inheritance with NamedTuple is not supported (reportGeneralTypeIssues)
 """
-conformance_automated = "Pass"
+conformance_automated = "Fail"
 errors_diff = """
+Line 76: Expected 1 errors
 """
diff --git a/conformance/results/pyright/namedtuples_define_functional.toml b/conformance/results/pyright/namedtuples_define_functional.toml
index 07c43204..37c5b7af 100644
--- a/conformance/results/pyright/namedtuples_define_functional.toml
+++ b/conformance/results/pyright/namedtuples_define_functional.toml
@@ -15,8 +15,11 @@ namedtuples_define_functional.py:43:17 - error: Argument of type "float" cannot
 namedtuples_define_functional.py:52:31 - error: Names within a named tuple must be unique (reportGeneralTypeIssues)
 namedtuples_define_functional.py:53:33 - error: Field names cannot be a keyword (reportGeneralTypeIssues)
 namedtuples_define_functional.py:54:33 - error: Field names cannot be a keyword (reportGeneralTypeIssues)
-namedtuples_define_functional.py:66:1 - error: Argument missing for parameter "a" (reportCallIssue)
+namedtuples_define_functional.py:60:1 - error: Argument missing for parameter "_d" (reportCallIssue)
+namedtuples_define_functional.py:60:13 - error: No parameter named "_1" (reportCallIssue)
+namedtuples_define_functional.py:69:1 - error: Argument missing for parameter "a" (reportCallIssue)
 """
-conformance_automated = "Pass"
+conformance_automated = "Fail"
 errors_diff = """
+Line 60: Unexpected errors ['namedtuples_define_functional.py:60:1 - error: Argument missing for parameter "_d" (reportCallIssue)', 'namedtuples_define_functional.py:60:13 - error: No parameter named "_1" (reportCallIssue)']
 """
diff --git a/conformance/results/pyright/version.toml b/conformance/results/pyright/version.toml
index 8fb908ad..86b0b4bd 100644
--- a/conformance/results/pyright/version.toml
+++ b/conformance/results/pyright/version.toml
@@ -1,2 +1,2 @@
-version = "pyright 1.1.398"
-test_duration = 2.3
+version = "pyright 1.1.399"
+test_duration = 1.5
diff --git a/conformance/results/pytype/namedtuples_define_class.toml b/conformance/results/pytype/namedtuples_define_class.toml
index 189add7c..c3213b93 100644
--- a/conformance/results/pytype/namedtuples_define_class.toml
+++ b/conformance/results/pytype/namedtuples_define_class.toml
@@ -59,7 +59,21 @@ namedtuples_define_class.py:49:7: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: i
 p10 = Point(1, 2, "", other="")  # E
       \u001b[1m\u001b[31m~~~~~~~~~~~~~~~~~~~~~~~~~\u001b[39m\u001b[0m
 
-namedtuples_define_class.py:95:1: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Any [assert-type]
+namedtuples_define_class.py:69:7: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Function Point2.__new__ expects 3 arg(s), got 4 [wrong-arg-count]
+
+p12 = Point2(1, 2, "")  # E
+      \u001b[1m\u001b[31m~~~~~~~~~~~~~~~~\u001b[39m\u001b[0m
+
+namedtuples_define_class.py:74:1: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: collections.namedtuple argument '_y' is not a valid typename or field name. [invalid-namedtuple-arg]
+
+class Point3(NamedTuple):
+\u001b[1m\u001b[31m~~~~~~~~~~~~~~~~~~~~~~~~~\u001b[39m\u001b[0m
+    x: int
+\u001b[1m\u001b[31m~~~~~~~~~~\u001b[39m\u001b[0m
+    _y: int  # E: illegal field name
+\u001b[1m\u001b[31m~~~~~~~~~~~\u001b[39m\u001b[0m
+
+namedtuples_define_class.py:122:1: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Any [assert-type]
 
 assert_type(pr1[1], float)
 \u001b[1m\u001b[31m~~~~~~~~~~~~~~~~~~~~~~~~~~\u001b[39m\u001b[0m
@@ -69,13 +83,15 @@ conformance_automated = "Fail"
 errors_diff = """
 Line 32: Expected 1 errors
 Line 33: Expected 1 errors
-Line 59: Expected 1 errors
-Line 79: Expected 1 errors
-Line 98: Expected 1 errors
-Line 105: Expected 1 errors
+Line 76: Expected 1 errors
+Line 86: Expected 1 errors
+Line 106: Expected 1 errors
+Line 125: Expected 1 errors
+Line 132: Expected 1 errors
 Line 27: Unexpected errors ['namedtuples_define_class.py:27:1: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: Union[int, str] [assert-type]']
 Line 28: Unexpected errors ['namedtuples_define_class.py:28:1: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: Union[int, str] [assert-type]']
 Line 29: Unexpected errors ['namedtuples_define_class.py:29:1: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: tuple[Union[int, str], ...] [assert-type]']
 Line 30: Unexpected errors ['namedtuples_define_class.py:30:1: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: tuple[Union[int, str], ...] [assert-type]']
-Line 95: Unexpected errors ['namedtuples_define_class.py:95:1: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: Any [assert-type]']
+Line 74: Unexpected errors ["namedtuples_define_class.py:74:1: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: collections.namedtuple argument '_y' is not a valid typename or field name. [invalid-namedtuple-arg]"]
+Line 122: Unexpected errors ['namedtuples_define_class.py:122:1: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: Any [assert-type]']
 """
diff --git a/conformance/results/pytype/namedtuples_define_functional.toml b/conformance/results/pytype/namedtuples_define_functional.toml
index f18a771b..981007f1 100644
--- a/conformance/results/pytype/namedtuples_define_functional.toml
+++ b/conformance/results/pytype/namedtuples_define_functional.toml
@@ -59,7 +59,12 @@ namedtuples_define_functional.py:54:7: \u001b[1m\u001b[31merror\u001b[39m\u001b[
 NT3 = namedtuple("NT3", ["abc", "def"], rename=False)  # E?: illegal field name
       \u001b[1m\u001b[31m~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\u001b[39m\u001b[0m
 
-namedtuples_define_functional.py:63:7: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Function collections.namedtuple was called with the wrong arguments [wrong-arg-types]
+namedtuples_define_functional.py:55:7: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: collections.namedtuple argument '_d' is not a valid typename or field name. [invalid-namedtuple-arg]
+
+NT4 = namedtuple("NT4", ["abc", "_d"], rename=False)  # E?: illegal field name
+      \u001b[1m\u001b[31m~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\u001b[39m\u001b[0m
+
+namedtuples_define_functional.py:66:7: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Function collections.namedtuple was called with the wrong arguments [wrong-arg-types]
 
 NT5 = namedtuple("NT5", "a b c", defaults=(1, 2))
       \u001b[1m\u001b[31m~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\u001b[39m\u001b[0m
@@ -67,6 +72,6 @@ NT5 = namedtuple("NT5", "a b c", defaults=(1, 2))
 """
 conformance_automated = "Fail"
 errors_diff = """
-Line 66: Expected 1 errors
-Line 63: Unexpected errors ['namedtuples_define_functional.py:63:7: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: Function collections.namedtuple was called with the wrong arguments [wrong-arg-types]']
+Line 69: Expected 1 errors
+Line 66: Unexpected errors ['namedtuples_define_functional.py:66:7: \\x1b[1m\\x1b[31merror\\x1b[39m\\x1b[0m: in <module>: Function collections.namedtuple was called with the wrong arguments [wrong-arg-types]']
 """
diff --git a/conformance/results/pytype/protocols_merging.toml b/conformance/results/pytype/protocols_merging.toml
index a3102a96..28275fdd 100644
--- a/conformance/results/pytype/protocols_merging.toml
+++ b/conformance/results/pytype/protocols_merging.toml
@@ -6,12 +6,12 @@ Does not report attempt to instantiate abstract class downgraded from protocol c
 output = """
 protocols_merging.py:52:1: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Type annotation for s6 does not match type of assignment [annotation-type-mismatch]
 
-s6: SizedAndClosable1 = SCConcrete2()  # E: doesn't implement close
+s6: SizedAndClosable1 = SCConcrete2()  # E: doesn't implement `__len__`
 \u001b[1m\u001b[31m~~\u001b[39m\u001b[0m
 
 protocols_merging.py:53:1: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Type annotation for s7 does not match type of assignment [annotation-type-mismatch]
 
-s7: SizedAndClosable2 = SCConcrete2()  # E: doesn't implement close
+s7: SizedAndClosable2 = SCConcrete2()  # E: doesn't implement `__len__`
 \u001b[1m\u001b[31m~~\u001b[39m\u001b[0m
 
 protocols_merging.py:54:1: \u001b[1m\u001b[31merror\u001b[39m\u001b[0m: in <module>: Type annotation for s8 does not match type of assignment [annotation-type-mismatch]
diff --git a/conformance/results/pytype/version.toml b/conformance/results/pytype/version.toml
index cdc0a953..364d7813 100644
--- a/conformance/results/pytype/version.toml
+++ b/conformance/results/pytype/version.toml
@@ -1,2 +1,2 @@
 version = "pytype 2024.10.11"
-test_duration = 43.3
+test_duration = 36.6
diff --git a/conformance/results/results.html b/conformance/results/results.html
index d78bd912..95af34a1 100644
--- a/conformance/results/results.html
+++ b/conformance/results/results.html
@@ -159,16 +159,16 @@ <h3>Python Type System Conformance Test Results</h3>
         <div class="table_container"><table><tbody>
 <tr><th class="col1">&nbsp;</th>
 <th class='tc-header'><div class='tc-name'>mypy 1.15.0</div>
-<div class='tc-time'>2.1sec</div>
+<div class='tc-time'>2.0sec</div>
 </th>
-<th class='tc-header'><div class='tc-name'>pyright 1.1.398</div>
-<div class='tc-time'>2.3sec</div>
+<th class='tc-header'><div class='tc-name'>pyright 1.1.399</div>
+<div class='tc-time'>1.5sec</div>
 </th>
 <th class='tc-header'><div class='tc-name'>pyre 0.9.23</div>
-<div class='tc-time'>3.9sec</div>
+<div class='tc-time'>7.3sec</div>
 </th>
 <th class='tc-header'><div class='tc-name'>pytype 2024.10.11</div>
-<div class='tc-time'>43.3sec</div>
+<div class='tc-time'>36.6sec</div>
 </th>
 </tr>
 <tr><th class="column" colspan="5">
@@ -445,10 +445,10 @@ <h3>Python Type System Conformance Test Results</h3>
 <a class="test_group" href="https://typing.readthedocs.io/en/latest/spec/class-compat.html">Class type compatibility</a>
 </th></tr>
 <tr><th class="column col1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;classes_classvar</th>
-<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Internal error if TypeVarTuple is used in ClassVar.</p><p>Does not reject use of ParamSpec in ClassVar.</p><p>Rejects ClassVar nested in Annotated.</p><p>Does not reject use of ClassVar in TypeAlias definition.</p><p>Does not infer type of ClassVar from assignment if no type is provided.</p></span></div></th>
+<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Internal error if TypeVarTuple is used in ClassVar.</p><p>Does not reject use of ParamSpec in ClassVar.</p><p>Rejects ClassVar nested in Annotated.</p><p>Does not reject use of ClassVar in TypeAlias definition.</p></span></div></th>
 <th class="column col2 conformant">Pass</th>
 <th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Does not reject use of TypeVar in ClassVar.</p><p>Does not reject use of ParamSpec in ClassVar.</p><p>Does not reject use of ClassVar as a generic type argument.</p><p>Does not reject use of ClassVar in parameter type annotation.</p><p>Does not reject use of ClassVar in local variable annotation.</p><p>Does not reject use of ClassVar in instance variable annotation.</p><p>Does not reject use of ClassVar in return type annotation.</p><p>Does not reject use of ClassVar in type alias definition.</p><p>Does not infer type from initialization for bare ClassVar.</p></span></div></th>
-<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Does not reject use of TypeVar in ClassVar.</p><p>Does not reject use of ParamSpec in ClassVar.</p><p>Does not reject use of ClassVar as a generic type argument.</p><p>Rejects initialization of ClassVar if no type argument is provided.</p><p>Does not reject use of ClassVar in parameter type annotation.</p><p>Does not reject use of ClassVar in local variable annotation.</p><p>Does not reject use of ClassVar in instance variable annotation.</p><p>Does not reject use of ClassVar in return type annotation.</p><p>Does not reject use of ClassVar in type alias definition.</p><p>Does not reject assignment of ClassVar through instance of class.</p></span></div></th>
+<th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Does not reject use of TypeVar in ClassVar.</p><p>Does not reject use of ParamSpec in ClassVar.</p><p>Does not reject use of ClassVar as a generic type argument.</p><p>Rejects initialization of ClassVar if no type argument is provided.</p><p>Does not infer ClassVar with no type argument and no assigned value as Any.</p><p>Does not reject use of ClassVar in parameter type annotation.</p><p>Does not reject use of ClassVar in local variable annotation.</p><p>Does not reject use of ClassVar in instance variable annotation.</p><p>Does not reject use of ClassVar in return type annotation.</p><p>Does not reject use of ClassVar in type alias definition.</p><p>Does not reject assignment of ClassVar through instance of class.</p></span></div></th>
 </tr>
 <tr><th class="column col1">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;classes_override</th>
 <th class="column col2 partially-conformant"><div class="hover-text">Partial<span class="tooltip-text" id="bottom"><p>Does not handle case where parent class derives from Any.</p></span></div></th>
diff --git a/conformance/tests/namedtuples_define_class.py b/conformance/tests/namedtuples_define_class.py
index e345a197..5e6e9c4c 100644
--- a/conformance/tests/namedtuples_define_class.py
+++ b/conformance/tests/namedtuples_define_class.py
@@ -49,6 +49,33 @@ class Point(NamedTuple):
 p10 = Point(1, 2, "", other="")  # E
 
 
+# > Fields must be annotated attributes - methods and un-annotated attributes are not
+# > considered fields.
+
+
+class Point2(NamedTuple):
+    x: int
+    y: int
+    units = "meters"  # Not a field
+
+    def is_origin(self) -> int:  # Not a field
+        return self.x == 0 and self.y == 0
+
+
+p11 = Point2(1, 2)
+assert_type(p11, Point2)
+x, y = p11
+
+p12 = Point2(1, 2, "")  # E
+
+
+# > Field names may not start with an underscore.
+
+class Point3(NamedTuple):
+    x: int
+    _y: int  # E: illegal field name
+
+
 # > The runtime implementation of ``NamedTuple`` enforces that fields with default
 # > values must come after fields without default values. Type checkers should
 # > likewise enforce this restriction::
diff --git a/conformance/tests/namedtuples_define_functional.py b/conformance/tests/namedtuples_define_functional.py
index 432dff73..51506e3d 100644
--- a/conformance/tests/namedtuples_define_functional.py
+++ b/conformance/tests/namedtuples_define_functional.py
@@ -43,18 +43,21 @@
 p6_4 = Point6(x=1.1, y=2)  # E
 
 
-# > At runtime, the ``namedtuple`` function disallows field names that are
-# > illegal Python identifiers and either raises an exception or replaces these
-# > fields with a parameter name of the form ``_N``. The behavior depends on
-# > the value of the ``rename`` argument. Type checkers may replicate this
-# > behavior statically.
+# > At runtime, the ``namedtuple`` function disallows field names that begin with
+# > an underscore or are illegal Python identifiers, and either raises an exception
+# > or replaces these fields with a parameter name of the form ``_N``. The behavior
+# > depends on the value of the ``rename`` argument. Type checkers may replicate
+# > this behavior statically.
 
 NT1 = namedtuple("NT1", ["a", "a"])  # E?: duplicate field name
 NT2 = namedtuple("NT2", ["abc", "def"])  # E?: illegal field name
 NT3 = namedtuple("NT3", ["abc", "def"], rename=False)  # E?: illegal field name
+NT4 = namedtuple("NT4", ["abc", "_d"], rename=False)  # E?: illegal field name
 
-NT4 = namedtuple("NT4", ["abc", "def"], rename=True)  # OK
-NT4(abc="", _1="")  # OK
+NT5 = namedtuple("NT5", ["abc", "def"], rename=True)  # OK
+NT5(abc="", _1="")  # OK
+NT6 = namedtuple("NT6", ["abc", "_d"], rename=True)  # OK
+NT6(abc="", _1="")  # OK
 
 
 # > The ``namedtuple`` function also supports a ``defaults`` keyword argument that
diff --git a/docs/spec/namedtuples.rst b/docs/spec/namedtuples.rst
index 1ac14136..936d2fa7 100644
--- a/docs/spec/namedtuples.rst
+++ b/docs/spec/namedtuples.rst
@@ -20,6 +20,14 @@ Type checkers should support the class syntax::
         y: int
         units: str = "meters"
 
+Fields must be annotated attributes - methods and un-annotated attributes are not
+considered fields. Field names may not start with an underscore.
+
+    class MyTuple(NamedTuple):
+        x1 = 1  # Not a field
+        def x2() -> None: pass  # Not a field
+        _x3: int  # Type error: illegal field name
+
 Regardless of whether the class syntax or factory function call is used to define
 a named tuple, type checkers should synthesize a ``__new__`` method based on
 the named tuple fields. This mirrors the runtime behavior. In the example
@@ -79,17 +87,21 @@ A type checker may support the factory function call in its various forms::
     Point5 = NamedTuple('Point5', [('x', int), ('y', int)])
     Point6 = NamedTuple('Point6', (('x', int), ('y', int)))
 
-At runtime, the ``namedtuple`` function disallows field names that are
-illegal Python identifiers and either raises an exception or replaces these
-fields with a parameter name of the form ``_N``. The behavior depends on
-the value of the ``rename`` argument. Type checkers may replicate this
-behavior statically::
+At runtime, the ``namedtuple`` function disallows field names that begin with
+an underscore or are illegal Python identifiers, and either raises an exception
+or replaces these fields with a parameter name of the form ``_N``. The behavior
+depends on the value of the ``rename`` argument. Type checkers may replicate
+this behavior statically::
 
     NT1 = namedtuple("NT1", ["a", "a"])  # Type error (duplicate field name)
     NT2 = namedtuple("NT2", ["abc", "def"], rename=False)  # Type error (illegal field name)
+    NT3 = namedtuple("NT3", ["abc", "_d"], rename=False)  # Type error (illegal field name)
+
+    NT4 = namedtuple("NT4", ["abc", "def"], rename=True)  # OK
+    NT4(abc="", _1="")  # OK
 
-    NT3 = namedtuple("NT3", ["abc", "def"], rename=True)  # OK
-    NT3(abc="", _1="")  # OK
+    NT5 = namedtuple("NT5", ["abc", "_d"], rename=True)  # OK
+    NT5(abc="", _1="")  # OK
 
 The ``namedtuple`` function also supports a ``defaults`` keyword argument that
 specifies default values for the fields. Type checkers may support this::