Docs: Documentation update. Copyright, licensing.

- Add Copyright placement guidance
- Clarify licencing information
- Remove a small typo

Signed-off-by: Anton Komlev <anton.komlev@arm.com>
Change-Id: I4c7cd0dd5607d6e60f6d7f1e87adefcc20006ba0
diff --git a/docs/contributing/coding_guide.rst b/docs/contributing/coding_guide.rst
index 3a59a41..e9f46f9 100644
--- a/docs/contributing/coding_guide.rst
+++ b/docs/contributing/coding_guide.rst
@@ -24,7 +24,7 @@
 
 .. Warning::
 
-    Text files do not fall within these rules as they may require different formatting.``
+    Text files do not fall within these rules as they may require different formatting.
 
 ****************
 Consistent style
diff --git a/docs/contributing/contributing_process.rst b/docs/contributing/contributing_process.rst
index 04cea4c..11dabda 100644
--- a/docs/contributing/contributing_process.rst
+++ b/docs/contributing/contributing_process.rst
@@ -32,6 +32,23 @@
     Use ``git commit -s`` to add a ``Signed-off-by`` trailer at the end of the
     commit log message.
     See `git-commit <https://git-scm.com/docs/git-commit>`_ for details.
+  - Ensure that each changed file has the correct copyright and license
+    information. Files that entirely consist of contributions to this project
+    should have a copyright notice and BSD-3-Clause SPDX license identifier of
+    the form as shown in :doc:`lic`. Files that contain changes to imported
+    Third Party IP files should retain their original copyright and license
+    notices.
+
+    Contributors can add the following copyright note, (whilst) it is suggested
+    to update copyright note only for *major*, non-trivial changes.
+
+    ::
+
+        Copyright (c) XXXX[-YYYY], <OWNER>. All rights reserved.
+
+    where XXXX is the year of first contribution and YYYY is the optional year
+    of most recent contribution. <OWNER> is your or your company name.
+
   - Add a `Change-Id <https://review.trustedfirmware.org/Documentation/user-changeid.html>`_
     to the commit message, which can be generated any way you like (e.g. from
     the SHA of the commit).
diff --git a/docs/introduction/readme.rst b/docs/introduction/readme.rst
index db37ead..82559cf 100644
--- a/docs/introduction/readme.rst
+++ b/docs/introduction/readme.rst
@@ -62,7 +62,21 @@
 
 - The ``bl2`` folder contains files imported from MCUBoot project and the files
   have Apache 2.0 license.
-- The ``lib`` folder may contain 3rd party files with diverse licenses.
+- The ``lib/ext`` folder may contain 3rd party projects and files with
+  diverse licenses. Here are some that are different from the BSD-3-Clause and
+  may be a part of the runtime image. The source code for these projects is
+  fetched from upstream at build time only.
+
+   - ``CMSIS_5``    - Apache 2.0 license
+   - ``mbedcrypto`` - `Apache 2.0 license MbedTLS
+     <https://github.com/Mbed-TLS/mbedtls/blob/development/LICENSE>`_
+   - ``mcuboot``    - `Apache 2.0 license MCUBoot
+     <https://github.com/mcu-tools/mcuboot/blob/main/LICENSE>`_
+   - ``qcbor``      - `Modified BSD-3-Clause license
+     <https://github.com/laurencelundblade/QCBOR#copyright-and-license>`_
+   - ``tf-m-extras`` - Set of additional components. Please check individually in
+     `tf-m-extras repository <https://git.trustedfirmware.org/TF-M/tf-m-extras.git/tree/>`_
+
 - The ``platform`` folder currently contains platforms support imported from
   the external project and the files may have different licenses.