Minor updates to address comments by @YannickJadoul from Dec 1, 2020.

Author: rwgk

docs/changelog.rst

@@ -6,7 +6,7 @@ Changelog
 Starting with version 1.8.0, pybind11 releases use a `semantic versioning
 <http://semver.org>`_ policy.
 
-v2.7.0 (WIP)
+v2.7.0 (TBA, not yet released)
 ------------------------------
 
 * ``py::str`` changed to exclusively hold `PyUnicodeObject`. Previously
@@ -16,11 +16,6 @@ v2.7.0 (WIP)
   `#2409 <https://github.com/pybind/pybind11/pull/2409>`_
 
 
-v2.6.3 (TBA, not yet released)
-------------------------------
-
-* Details to follow here
-
 v2.6.2 (Jan 26, 2021)
 ---------------------
 

docs/upgrade.rst

@@ -18,10 +18,10 @@ and ``py::isinstance<str>()`` is ``true`` for both ``py::str`` and
 ``py::bytes``. Starting with v2.7, ``py::str`` exclusively holds
 ``PyUnicodeObject`` (`#2409 <https://github.com/pybind/pybind11/pull/2409>`_),
 and ``py::isinstance<str>()`` is ``true`` only for ``py::str``. To help in
-the transition of client code, the ``PYBIND11_STR_LEGACY_PERMISSIVE`` macro
+the transition of user code, the ``PYBIND11_STR_LEGACY_PERMISSIVE`` macro
 is provided as an escape hatch to go back to the legacy behavior. This macro
-will be removed in future releases. Two types of required client-code fixes
-are expected to be common:
+will be removed in future releases. Two types of required fixes are expected
+to be common:
 
 * Accidental use of ``py::str`` instead of ``py::bytes``, masked by the legacy
   behavior. These are probably very easy to fix, by changing from