diff --git a/Include/internal/pycore_ast.h b/Include/internal/pycore_ast.h
index b568902bb1e381..f222d485e0b54b 100644
--- a/Include/internal/pycore_ast.h
+++ b/Include/internal/pycore_ast.h
@@ -10,7 +10,7 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_asdl.h"
+#include "pycore_asdl.h"          // _ASDL_SEQ_HEAD
 
 typedef struct _mod *mod_ty;
 
diff --git a/Include/internal/pycore_atomic.h b/Include/internal/pycore_atomic.h
index 425d69f868b52b..48d246ea08f3d9 100644
--- a/Include/internal/pycore_atomic.h
+++ b/Include/internal/pycore_atomic.h
@@ -8,19 +8,19 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "dynamic_annotations.h"   /* _Py_ANNOTATE_MEMORY_ORDER */
-#include "pyconfig.h"
+#include "pyconfig.h"             // HAVE_STD_ATOMIC
+#include "dynamic_annotations.h"  // _Py_ANNOTATE_MEMORY_ORDER
 
 #ifdef HAVE_STD_ATOMIC
-#  include <stdatomic.h>
+#  include <stdatomic.h>          // atomic_store_explicit()
 #endif
 
 
 #if defined(_MSC_VER)
-#include <intrin.h>
-#if defined(_M_IX86) || defined(_M_X64)
-#  include <immintrin.h>
-#endif
+#  include <intrin.h>             // _InterlockedExchange64()
+#  if defined(_M_IX86) || defined(_M_X64)
+#    include <immintrin.h>        // _InterlockedExchange_HLEAcquire()
+#  endif
 #endif
 
 /* This is modeled after the atomics interface from C1x, according to
diff --git a/Include/internal/pycore_bitutils.h b/Include/internal/pycore_bitutils.h
index e6bf61ef425bd8..50f69377523818 100644
--- a/Include/internal/pycore_bitutils.h
+++ b/Include/internal/pycore_bitutils.h
@@ -26,10 +26,10 @@ extern "C" {
 #endif
 
 #ifdef _MSC_VER
-   /* Get _byteswap_ushort(), _byteswap_ulong(), _byteswap_uint64() */
-#  include <intrin.h>
+#  include <intrin.h>             // _byteswap_uint64()
 #endif
 
+
 static inline uint16_t
 _Py_bswap16(uint16_t word)
 {
diff --git a/Include/internal/pycore_ceval.h b/Include/internal/pycore_ceval.h
index 0e3a99be8c36aa..f32ed3b7e30b7e 100644
--- a/Include/internal/pycore_ceval.h
+++ b/Include/internal/pycore_ceval.h
@@ -8,6 +8,9 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+#include "pycore_interp.h"        // PyInterpreterState.eval_frame
+#include "pycore_pystate.h"       // _PyThreadState_GET()
+
 /* Forward declarations */
 struct pyruntimestate;
 struct _ceval_runtime_state;
@@ -16,10 +19,6 @@ struct _ceval_runtime_state;
 #  define Py_DEFAULT_RECURSION_LIMIT 1000
 #endif
 
-#include "pycore_interp.h"        // PyInterpreterState.eval_frame
-#include "pycore_pystate.h"       // _PyThreadState_GET()
-
-
 extern void _Py_FinishPendingCalls(PyThreadState *tstate);
 extern void _PyEval_InitState(PyInterpreterState *, PyThread_type_lock);
 extern void _PyEval_FiniState(struct _ceval_state *ceval);
diff --git a/Include/internal/pycore_ceval_state.h b/Include/internal/pycore_ceval_state.h
index 1ebfcc9bebd0ab..6e3d669dc646af 100644
--- a/Include/internal/pycore_ceval_state.h
+++ b/Include/internal/pycore_ceval_state.h
@@ -8,8 +8,6 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-
-#include "pycore_atomic.h"          /* _Py_atomic_address */
 #include "pycore_gil.h"             // struct _gil_runtime_state
 
 
diff --git a/Include/internal/pycore_condvar.h b/Include/internal/pycore_condvar.h
index 981c962bf7dfdf..db8682a4c077aa 100644
--- a/Include/internal/pycore_condvar.h
+++ b/Include/internal/pycore_condvar.h
@@ -10,7 +10,7 @@
    not present in unistd.h. But they still can be implemented as an external
    library (e.g. gnu pth in pthread emulation) */
 # ifdef HAVE_PTHREAD_H
-#  include <pthread.h> /* _POSIX_THREADS */
+#  include <pthread.h>            // _POSIX_THREADS
 # endif
 #endif
 
@@ -21,7 +21,7 @@
 #define Py_HAVE_CONDVAR
 
 #ifdef HAVE_PTHREAD_H
-#  include <pthread.h>
+#  include <pthread.h>            // pthread_mutex_t
 #endif
 
 #define PyMUTEX_T pthread_mutex_t
@@ -38,7 +38,7 @@
 
 /* include windows if it hasn't been done before */
 #define WIN32_LEAN_AND_MEAN
-#include <windows.h>
+#include <windows.h>              // CRITICAL_SECTION
 
 /* options */
 /* non-emulated condition variables are provided for those that want
diff --git a/Include/internal/pycore_context.h b/Include/internal/pycore_context.h
index 52dfe3ef233874..f1898cf873312b 100644
--- a/Include/internal/pycore_context.h
+++ b/Include/internal/pycore_context.h
@@ -5,7 +5,7 @@
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_hamt.h"   /* PyHamtObject */
+#include "pycore_hamt.h"          // PyHamtObject
 
 
 extern PyTypeObject _PyContextTokenMissing_Type;
diff --git a/Include/internal/pycore_dict.h b/Include/internal/pycore_dict.h
index 2ad6ef0f7c04d5..df7bc7e58f6c97 100644
--- a/Include/internal/pycore_dict.h
+++ b/Include/internal/pycore_dict.h
@@ -9,9 +9,7 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_dict_state.h"
-#include "pycore_object.h"
-#include "pycore_runtime.h"         // _PyRuntime
+#include "pycore_object.h"        // PyDictOrValues
 
 // Unsafe flavor of PyDict_GetItemWithError(): no error checking
 extern PyObject* _PyDict_GetItemWithError(PyObject *dp, PyObject *key);
diff --git a/Include/internal/pycore_faulthandler.h b/Include/internal/pycore_faulthandler.h
index e6aec7745a6479..6dd7d8d7ca9792 100644
--- a/Include/internal/pycore_faulthandler.h
+++ b/Include/internal/pycore_faulthandler.h
@@ -9,7 +9,7 @@ extern "C" {
 #endif
 
 #ifdef HAVE_SIGACTION
-#  include <signal.h>
+#  include <signal.h>             // sigaction
 #endif
 
 
diff --git a/Include/internal/pycore_fileutils.h b/Include/internal/pycore_fileutils.h
index 25b383b9780adc..96e3d1c7abcdde 100644
--- a/Include/internal/pycore_fileutils.h
+++ b/Include/internal/pycore_fileutils.h
@@ -8,7 +8,8 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include <locale.h>   /* struct lconv */
+#include <locale.h>               // struct lconv
+
 
 /* A routine to check if a file descriptor can be select()-ed. */
 #ifdef _MSC_VER
@@ -268,7 +269,7 @@ extern wchar_t *_Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t
 // so provide our own implementations. Remove them in case they get added
 // to the Games API family
 #if defined(MS_WINDOWS_GAMES) && !defined(MS_WINDOWS_DESKTOP)
-#include <winerror.h>
+#include <winerror.h>             // HRESULT
 
 extern HRESULT PathCchSkipRoot(const wchar_t *pszPath, const wchar_t **ppszRootEnd);
 #endif /* defined(MS_WINDOWS_GAMES) && !defined(MS_WINDOWS_DESKTOP) */
diff --git a/Include/internal/pycore_gil.h b/Include/internal/pycore_gil.h
index 8ebad37b686cd4..a1a15070eef461 100644
--- a/Include/internal/pycore_gil.h
+++ b/Include/internal/pycore_gil.h
@@ -8,8 +8,8 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_atomic.h"    /* _Py_atomic_address */
-#include "pycore_condvar.h"   /* PyCOND_T */
+#include "pycore_atomic.h"        // _Py_atomic_address
+#include "pycore_condvar.h"       // PyCOND_T
 
 #ifndef Py_HAVE_CONDVAR
 #  error You need either a POSIX-compatible or a Windows system!
diff --git a/Include/internal/pycore_global_objects.h b/Include/internal/pycore_global_objects.h
index 442f8516278b02..327fcc24cb29f1 100644
--- a/Include/internal/pycore_global_objects.h
+++ b/Include/internal/pycore_global_objects.h
@@ -8,11 +8,11 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_hashtable.h"       // _Py_hashtable_t
-#include "pycore_gc.h"              // PyGC_Head
+#include "pycore_context.h"         // _PyContextTokenMissing
+#include "pycore_gc.h"              // _PyGC_Head_UNUSED
 #include "pycore_global_strings.h"  // struct _Py_global_strings
 #include "pycore_hamt.h"            // PyHamtNode_Bitmap
-#include "pycore_context.h"         // _PyContextTokenMissing
+#include "pycore_hashtable.h"       // _Py_hashtable_t
 #include "pycore_typeobject.h"      // pytype_slotdef
 
 
diff --git a/Include/internal/pycore_import.h b/Include/internal/pycore_import.h
index 34f572bd592969..e23f9931cea734 100644
--- a/Include/internal/pycore_import.h
+++ b/Include/internal/pycore_import.h
@@ -103,7 +103,7 @@ struct _import_state {
 };
 
 #ifdef HAVE_DLOPEN
-#  include <dlfcn.h>
+#  include <dlfcn.h>              // RTLD_NOW, RTLD_LAZY
 #  if HAVE_DECL_RTLD_NOW
 #    define _Py_DLOPEN_FLAGS RTLD_NOW
 #  else
diff --git a/Include/internal/pycore_instruments.h b/Include/internal/pycore_instruments.h
index e15447acec2c0c..43214aef7f7a1b 100644
--- a/Include/internal/pycore_instruments.h
+++ b/Include/internal/pycore_instruments.h
@@ -6,9 +6,7 @@
 #endif
 
 #include "pycore_bitutils.h"      // _Py_popcount32
-#include "pycore_frame.h"
-
-#include "cpython/code.h"
+#include "pycore_frame.h"         // _PyInterpreterFrame
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/Include/internal/pycore_interp.h b/Include/internal/pycore_interp.h
index 91c473e58eaba2..c21c352608d161 100644
--- a/Include/internal/pycore_interp.h
+++ b/Include/internal/pycore_interp.h
@@ -8,7 +8,7 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include <stdbool.h>
+#include <stdbool.h>              // bool
 
 #include "pycore_ast_state.h"     // struct ast_state
 #include "pycore_atexit.h"        // struct atexit_state
@@ -21,16 +21,16 @@ extern "C" {
 #include "pycore_exceptions.h"    // struct _Py_exc_state
 #include "pycore_floatobject.h"   // struct _Py_float_state
 #include "pycore_function.h"      // FUNC_MAX_WATCHERS
-#include "pycore_genobject.h"     // struct _Py_async_gen_state
 #include "pycore_gc.h"            // struct _gc_runtime_state
-#include "pycore_global_objects.h"  // struct _Py_interp_static_objects
+#include "pycore_genobject.h"     // struct _Py_async_gen_state
+#include "pycore_global_objects.h"// struct _Py_interp_cached_objects
 #include "pycore_import.h"        // struct _import_state
 #include "pycore_instruments.h"   // _PY_MONITORING_EVENTS
 #include "pycore_list.h"          // struct _Py_list_state
-#include "pycore_object_state.h"   // struct _py_object_state
-#include "pycore_obmalloc.h"      // struct obmalloc_state
+#include "pycore_object_state.h"  // struct _py_object_state
+#include "pycore_obmalloc.h"      // struct _obmalloc_state
 #include "pycore_tuple.h"         // struct _Py_tuple_state
-#include "pycore_typeobject.h"    // struct type_cache
+#include "pycore_typeobject.h"    // struct types_state
 #include "pycore_unicodeobject.h" // struct _Py_unicode_state
 #include "pycore_warnings.h"      // struct _warnings_runtime_state
 
diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
index 857d6efec3b3b1..5e2d13a5220556 100644
--- a/Include/internal/pycore_object.h
+++ b/Include/internal/pycore_object.h
@@ -12,7 +12,6 @@ extern "C" {
 #include "pycore_gc.h"            // _PyObject_GC_IS_TRACKED()
 #include "pycore_interp.h"        // PyInterpreterState.gc
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
-#include "pycore_runtime.h"       // _PyRuntime
 
 /* Check if an object is consistent. For example, ensure that the reference
    counter is greater than or equal to 1, and ensure that ob_type is not NULL.
diff --git a/Include/internal/pycore_opcode_metadata.h b/Include/internal/pycore_opcode_metadata.h
index fab91e611b6175..e35db0c4c5a59d 100644
--- a/Include/internal/pycore_opcode_metadata.h
+++ b/Include/internal/pycore_opcode_metadata.h
@@ -7,7 +7,7 @@
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include <stdbool.h>
+#include <stdbool.h>              // bool
 
 
 #define IS_PSEUDO_INSTR(OP)  ( \
diff --git a/Include/internal/pycore_opcode_utils.h b/Include/internal/pycore_opcode_utils.h
index 50ff2af38d2cbe..f17612908cebdc 100644
--- a/Include/internal/pycore_opcode_utils.h
+++ b/Include/internal/pycore_opcode_utils.h
@@ -8,7 +8,7 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_opcode.h"        // _PyOpcode_Jump
+#include "pycore_opcode.h"        // JUMP_FORWARD
 
 
 #define MAX_REAL_OPCODE 254
diff --git a/Include/internal/pycore_optimizer.h b/Include/internal/pycore_optimizer.h
index 2ae657c4e117ff..f9f16c48cbc21c 100644
--- a/Include/internal/pycore_optimizer.h
+++ b/Include/internal/pycore_optimizer.h
@@ -8,7 +8,7 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_uops.h"
+#include "pycore_uops.h"          // _PyUOpInstruction
 
 int _Py_uop_analyze_and_optimize(PyCodeObject *code,
     _PyUOpInstruction *trace, int trace_len, int curr_stackentries);
diff --git a/Include/internal/pycore_pymem_init.h b/Include/internal/pycore_pymem_init.h
index 78232738cb09d5..119fa16fb911ae 100644
--- a/Include/internal/pycore_pymem_init.h
+++ b/Include/internal/pycore_pymem_init.h
@@ -8,8 +8,6 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_pymem.h"
-
 
 /********************************/
 /* the allocators' initializers */
diff --git a/Include/internal/pycore_pystate.h b/Include/internal/pycore_pystate.h
index acc6cf953343fb..f6ca9102b139e6 100644
--- a/Include/internal/pycore_pystate.h
+++ b/Include/internal/pycore_pystate.h
@@ -8,7 +8,7 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_runtime.h"   /* PyRuntimeState */
+#include "pycore_runtime.h"       // _PyRuntime
 
 
 /* Check if the current thread is the main thread.
diff --git a/Include/internal/pycore_pythread.h b/Include/internal/pycore_pythread.h
index f53921494c158f..44846c0fc4b4c3 100644
--- a/Include/internal/pycore_pythread.h
+++ b/Include/internal/pycore_pythread.h
@@ -13,9 +13,9 @@ extern "C" {
 /* This means pthreads are not implemented in libc headers, hence the macro
    not present in unistd.h. But they still can be implemented as an external
    library (e.g. gnu pth in pthread emulation) */
-# ifdef HAVE_PTHREAD_H
-#  include <pthread.h> /* _POSIX_THREADS */
-# endif
+#  ifdef HAVE_PTHREAD_H
+#    include <pthread.h>            // _POSIX_THREADS
+#  endif
 # ifndef _POSIX_THREADS
 /* Check if we're running on HP-UX and _SC_THREADS is defined. If so, then
    enough of the Posix threads package is implemented to support python
@@ -34,12 +34,12 @@ extern "C" {
 #endif /* _POSIX_THREADS */
 
 #if defined(_POSIX_THREADS) || defined(HAVE_PTHREAD_STUBS)
-# define _USE_PTHREADS
+#  define _USE_PTHREADS
 #endif
 
 #if defined(_USE_PTHREADS) && defined(HAVE_PTHREAD_CONDATTR_SETCLOCK) && defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
 // monotonic is supported statically.  It doesn't mean it works on runtime.
-# define CONDATTR_MONOTONIC
+#  define CONDATTR_MONOTONIC
 #endif
 
 
diff --git a/Include/internal/pycore_runtime.h b/Include/internal/pycore_runtime.h
index 63b485027486bb..4a460803c69bde 100644
--- a/Include/internal/pycore_runtime.h
+++ b/Include/internal/pycore_runtime.h
@@ -8,24 +8,23 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_atexit.h"          // struct atexit_runtime_state
-#include "pycore_atomic.h"          /* _Py_atomic_address */
+#include "pycore_atexit.h"          // struct _atexit_runtime_state
+#include "pycore_atomic.h"          // _Py_atomic_address
 #include "pycore_ceval_state.h"     // struct _ceval_runtime_state
-#include "pycore_floatobject.h"     // struct _Py_float_runtime_state
 #include "pycore_faulthandler.h"    // struct _faulthandler_runtime_state
-#include "pycore_global_objects.h"  // struct _Py_global_objects
+#include "pycore_floatobject.h"     // struct _Py_float_runtime_state
 #include "pycore_import.h"          // struct _import_runtime_state
 #include "pycore_interp.h"          // PyInterpreterState
 #include "pycore_object_state.h"    // struct _py_object_runtime_state
 #include "pycore_parser.h"          // struct _parser_runtime_state
-#include "pycore_pymem.h"           // struct _pymem_allocators
 #include "pycore_pyhash.h"          // struct pyhash_runtime_state
+#include "pycore_pymem.h"           // struct _pymem_allocators
 #include "pycore_pythread.h"        // struct _pythread_runtime_state
 #include "pycore_signal.h"          // struct _signals_runtime_state
 #include "pycore_time.h"            // struct _time_runtime_state
 #include "pycore_tracemalloc.h"     // struct _tracemalloc_runtime_state
-#include "pycore_typeobject.h"      // struct types_runtime_state
-#include "pycore_unicodeobject.h"   // struct _Py_unicode_runtime_ids
+#include "pycore_typeobject.h"      // struct _types_runtime_state
+#include "pycore_unicodeobject.h"   // struct _Py_unicode_runtime_state
 
 struct _getargs_runtime_state {
     PyThread_type_lock mutex;
diff --git a/Include/internal/pycore_runtime_init.h b/Include/internal/pycore_runtime_init.h
index ea29c69f59acc7..c775a8a7e7eefa 100644
--- a/Include/internal/pycore_runtime_init.h
+++ b/Include/internal/pycore_runtime_init.h
@@ -8,11 +8,17 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_long.h"
-#include "pycore_object.h"
-#include "pycore_parser.h"
-#include "pycore_pymem_init.h"
-#include "pycore_obmalloc_init.h"
+#include "pycore_ceval_state.h"   // _PyEval_RUNTIME_PERF_INIT
+#include "pycore_faulthandler.h"  // _faulthandler_runtime_state_INIT
+#include "pycore_floatobject.h"   // _py_float_format_unknown
+#include "pycore_object.h"        // _PyObject_HEAD_INIT
+#include "pycore_obmalloc_init.h" // _obmalloc_global_state_INIT
+#include "pycore_parser.h"        // _parser_runtime_state_INIT
+#include "pycore_pyhash.h"        // pyhash_state_INIT
+#include "pycore_pymem_init.h"    // _pymem_allocators_standard_INIT
+#include "pycore_runtime_init_generated.h"  // _Py_bytes_characters_INIT
+#include "pycore_signal.h"        // _signals_RUNTIME_INIT
+#include "pycore_tracemalloc.h"   // _tracemalloc_runtime_state_INIT
 
 
 extern PyTypeObject _PyExc_MemoryError;
diff --git a/Include/internal/pycore_runtime_init_generated.h b/Include/internal/pycore_runtime_init_generated.h
index 8c0fcdb1bdae1c..694a409fbf4f47 100644
--- a/Include/internal/pycore_runtime_init_generated.h
+++ b/Include/internal/pycore_runtime_init_generated.h
@@ -8,6 +8,9 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+#include "pycore_long.h"          // _PyLong_DIGIT_INIT()
+
+
 /* The following is auto-generated by Tools/build/generate_global_objects.py. */
 #define _Py_small_ints_INIT { \
     _PyLong_DIGIT_INIT(-5), \
diff --git a/Include/internal/pycore_signal.h b/Include/internal/pycore_signal.h
index 46b57d556e5ef4..8f876759c0d07f 100644
--- a/Include/internal/pycore_signal.h
+++ b/Include/internal/pycore_signal.h
@@ -10,8 +10,8 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-#include "pycore_atomic.h"         // _Py_atomic_address
-#include <signal.h>                // NSIG
+#include "pycore_atomic.h"        // _Py_atomic_address
+#include <signal.h>               // NSIG
 
 
 // Restore signals that the interpreter has called SIG_IGN on to SIG_DFL.
diff --git a/Include/internal/pycore_typeobject.h b/Include/internal/pycore_typeobject.h
index aba672effe3928..4d6a0189c4afee 100644
--- a/Include/internal/pycore_typeobject.h
+++ b/Include/internal/pycore_typeobject.h
@@ -4,12 +4,12 @@
 extern "C" {
 #endif
 
-#include "pycore_moduleobject.h"
-
 #ifndef Py_BUILD_CORE
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+#include "pycore_moduleobject.h"  // PyModuleObject
+
 
 /* state */
 
diff --git a/Modules/_json.c b/Modules/_json.c
index c7cfe50b52faff..41495e2012f152 100644
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -12,7 +12,7 @@
 #include "pycore_ceval.h"           // _Py_EnterRecursiveCall()
 #include "pycore_runtime.h"         // _PyRuntime
 
-#include "pycore_global_objects.h"  // _Py_ID()
+#include "pycore_global_strings.h"  // _Py_ID()
 #include <stdbool.h>                // bool
 
 
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 35599f8baa204d..a7a98d1eea5bd1 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -18,8 +18,8 @@
 #undef NDEBUG
 
 #include "Python.h"
-#include "frameobject.h"          // PyFrame_New
-#include "marshal.h"              // PyMarshal_WriteLongToFile
+#include "frameobject.h"          // PyFrame_New()
+#include "marshal.h"              // PyMarshal_WriteLongToFile()
 
 #include <float.h>                // FLT_MAX
 #include <signal.h>
@@ -37,7 +37,7 @@
 #endif
 
 #ifdef bool
-#  error "The public headers should not include <stdbool.h>, see bpo-46748"
+#  error "The public headers should not include <stdbool.h>, see gh-48924"
 #endif
 
 // Several parts of this module are broken out into files in _testcapi/.
diff --git a/Modules/_testinternalcapi.c b/Modules/_testinternalcapi.c
index d1082c7dae8aee..5571ae463373e0 100644
--- a/Modules/_testinternalcapi.c
+++ b/Modules/_testinternalcapi.c
@@ -10,26 +10,24 @@
 #undef NDEBUG
 
 #include "Python.h"
-#include "pycore_atomic_funcs.h" // _Py_atomic_int_get()
-#include "pycore_bitutils.h"     // _Py_bswap32()
-#include "pycore_bytesobject.h"  // _PyBytes_Find()
-#include "pycore_compile.h"      // _PyCompile_CodeGen, _PyCompile_OptimizeCfg, _PyCompile_Assemble, _PyCompile_CleanDoc
-#include "pycore_ceval.h"        // _PyEval_AddPendingCall
-#include "pycore_dict.h"        // _PyDictOrValues_GetValues
-#include "pycore_fileutils.h"    // _Py_normpath
-#include "pycore_frame.h"        // _PyInterpreterFrame
-#include "pycore_gc.h"           // PyGC_Head
-#include "pycore_hashtable.h"    // _Py_hashtable_new()
-#include "pycore_initconfig.h"   // _Py_GetConfigsAsDict()
-#include "pycore_interp.h"       // _PyInterpreterState_GetConfigCopy()
-#include "pycore_object.h"       // _PyObject_IsFreed()
-#include "pycore_pathconfig.h"   // _PyPathConfig_ClearGlobal()
-#include "pycore_pyerrors.h"     // _Py_UTF8_Edit_Cost()
-#include "pycore_pystate.h"      // _PyThreadState_GET()
-
-#include "frameobject.h"
-#include "interpreteridobject.h" // PyInterpreterID_LookUp()
-#include "osdefs.h"              // MAXPATHLEN
+#include "pycore_atomic_funcs.h"  // _Py_atomic_int_get()
+#include "pycore_bitutils.h"      // _Py_bswap32()
+#include "pycore_bytesobject.h"   // _PyBytes_Find()
+#include "pycore_compile.h"       // _PyCompile_CodeGen, _PyCompile_OptimizeCfg, _PyCompile_Assemble, _PyCompile_CleanDoc
+#include "pycore_ceval.h"         // _PyEval_AddPendingCall
+#include "pycore_dict.h"          // _PyDictOrValues_GetValues()
+#include "pycore_fileutils.h"     // _Py_normpath
+#include "pycore_frame.h"         // _PyInterpreterFrame
+#include "pycore_gc.h"            // PyGC_Head
+#include "pycore_hashtable.h"     // _Py_hashtable_new()
+#include "pycore_initconfig.h"    // _Py_GetConfigsAsDict()
+#include "pycore_interp.h"        // _PyInterpreterState_GetConfigCopy()
+#include "pycore_object.h"        // _PyObject_IsFreed()
+#include "pycore_pathconfig.h"    // _PyPathConfig_ClearGlobal()
+#include "pycore_pyerrors.h"      // _Py_UTF8_Edit_Cost()
+#include "pycore_pystate.h"       // _PyThreadState_GET()
+
+#include "interpreteridobject.h"  // PyInterpreterID_LookUp()
 
 #include "clinic/_testinternalcapi.c.h"
 
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 1733cd4b15aa4c..bf144871bb7364 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -1585,7 +1585,7 @@ def write_header(mod, metadata, f):
         #  error "this header requires Py_BUILD_CORE define"
         #endif
 
-        #include "pycore_asdl.h"
+        #include "pycore_asdl.h"          // _ASDL_SEQ_HEAD
 
     """).lstrip())
 
diff --git a/Tools/cases_generator/generate_cases.py b/Tools/cases_generator/generate_cases.py
index c3b729df44a6a2..6ee68363058116 100644
--- a/Tools/cases_generator/generate_cases.py
+++ b/Tools/cases_generator/generate_cases.py
@@ -410,7 +410,7 @@ def write_metadata(self, metadata_filename: str, pymetadata_filename: str) -> No
                 #endif
             """).strip())
 
-            self.out.emit("\n#include <stdbool.h>")
+            self.out.emit("\n#include <stdbool.h>              // bool")
 
             self.write_pseudo_instrs()