clarification of the release instructions

CONTRIBUTING.rst

@@ -86,7 +86,9 @@ How-to make a release
 ---------------------
 
 Use cases
-+++++++++++++
++++++++++
+
+The `release branch` is the ``main`` branch, except for bug fix releases.
 
 Release candidates
 ..................
@@ -97,49 +99,54 @@ Major/minor releases
 ....................
 
 Follow this release process.
+
 Bug fix releases
 ................
 
-- For ``vM.m.1``, first create a ``M.m`` branch from the ``vM.m.0`` tag.
+- For ``vM.m.1``, first create a ``M.m`` branch from the ``vM.m.0`` tag when not already done.
 - Merge relevant pull requests on the ``M.m`` branch.
-- Follow this release process, but for the branch ``M.m`` instead of ``main``.
+- Follow this release process, but with release branch ``M.m`` instead of ``main``.
 
 Pre-release testing
 +++++++++++++++++++
 
 Automated tests
 ...............
 
-- Run the `release workflow`_ manually (see `manually running a workflow`_) to check that the release artifacts are built correctly.
+- Run the `release workflow`_ called "Build and deploy" manually on the release branch (see `manually running a workflow`_).
+  This is to verify that the release artifacts are built correctly.
   The wheels generated by the workflow can be downloaded from the release workflow run web page.
-  *Note: Running the workflow manually do NOT publish artifacts to pypi.*
+  *Note: Running the workflow manually does NOT publish artifacts to pypi.*
 
-- Run the `previous release workflow`_ with the following variables:
+- Run the `bob workflow`_ with the following variables:
   - ``REPOSITORY``: ``https://github.com/<user>/silx`` (default: ``https://github.com/silx-kit/silx``)
   - ``TAG``: branch or tag to test (default: ``main`` branch)
 
 Manual testing
 ..............
 
-Download wheels generated by the github release workflow from the github action release workflow web page and install silx from those wheels locally for manual testing.
+Download wheels generated by the github release workflow from the github action release workflow web page and install silx
+from those wheels locally for manual testing.
 
 Prepare the release
 +++++++++++++++++++
 
 Write the release notes
 .......................
 
-- Generate the list of pull requests included in the release with github's automatically generated release notes (see `github automatically generated release notes`_) between a new tag and the previous release.
+- Generate the list of pull requests included in the release with github's automatically generated release notes
+  (see `github automatically generated release notes`_) between a new tag and the previous release.
 - Copy the generated changelog to ``CHANGELOG.rst`` and close github's release web page.
   **Warning: DO NOT publish the release yet!**
 - Sort, curate and fix the list of PRs and match the styling of previous release notes.
 
 Steps
 .....
 
+- Create a branch from the release branch.
 - Update ``CHANGELOG.rst``.
 - Bump the version number in ``src/silx/_version.py``.
-- Create a pull request with those changes, wait for reviews and merge it.
+- Create a pull request to the release branch with those changes, wait for reviews and merge it.
 
 Publish the release
 +++++++++++++++++++
@@ -149,13 +156,14 @@ Create the release
 
 * Draft a new release from `github new release page`_ using similar conventions as previous releases:
   - Create a new tag which **MUST** be named ``v<release_version>`` and match the version in ``src/silx/_version.py``.
+  - Select the release branch as the target.
   - Combine the release notes manually edited from ``CHANGELOG.rst`` with `github automatically generated release notes`_.
-* Press the "Publish release" button to trigger the release workflow which builds the documentation, the source tarball, the wheels and the Windows "fat binaries".
+* Press the "Publish release" button to push the new tag to the release branch and trigger the release workflow which builds
+  the documentation, the source tarball, the wheels and the Windows "fat binaries" of the release.
 
 Publish Windows "fat binaries"
 ..............................
 
-
 Once Windows "fat binaries" are built and tested, the release workflow requests the approval from a reviewer of the "assets" `deployment environment`_.
 Upon approval, the following files are added to the github release assets:
 
@@ -189,7 +197,7 @@ Once this PR is merged, the new version is published on conda-forge.
 .. _manually running a workflow: https://docs.github.com/en/actions/using-workflows/manually-running-a-workflow
 .. _github new release page: https://github.com/silx-kit/silx/releases/new
 .. _github automatically generated release notes: https://docs.github.com/en/repositories/releasing-projects-on-github/automatically-generated-release-notes#creating-automatically-generated-release-notes-for-a-new-release
-.. _previous release workflow: https://gitlab.esrf.fr/silx/bob/silx/-/pipelines/new
+.. _bob workflow: https://gitlab.esrf.fr/silx/bob/silx/-/pipelines/new
 .. _deployment environment: https://github.com/silx-kit/silx/settings/environments
 .. _pypi: https://pypi.org/project/silx/
 .. _silx feedstock: https://github.com/conda-forge/silx-feedstock