Fix note markup (#16805).
Patch by Tshepang Lekhonkhobe, reviewed by Georg Brandl.
diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst
index 58c0f3d..28a434e 100644
--- a/Doc/c-api/arg.rst
+++ b/Doc/c-api/arg.rst
@@ -45,6 +45,7 @@
Unless otherwise stated, buffers are not NUL-terminated.
.. note::
+
For all ``#`` variants of formats (``s#``, ``y#``, etc.), the type of
the length argument (int or :c:type:`Py_ssize_t`) is controlled by
defining the macro :c:macro:`PY_SSIZE_T_CLEAN` before including
diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst
index 705509f..4dad2c8 100644
--- a/Doc/c-api/init.rst
+++ b/Doc/c-api/init.rst
@@ -548,6 +548,7 @@
.. index:: module: _thread
.. note::
+
When only the main thread exists, no GIL operations are needed. This is a
common situation (most Python programs do not use threads), and the lock
operations slow the interpreter down a bit. Therefore, the lock is not