CONTRIBUTING.md: Improve backport instructions

1 files changed, 5 insertions, 4 deletions

diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index ae4f68dddc1..cb0264b0167 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -50,12 +50,13 @@ For package version upgrades and such a one-line commit message is usually suffi
 
 ## Backporting changes
 
-To [backport a change into a release branch](https://nixos.org/nixpkgs/manual/#submitting-changes-stable-release-branches):
+Follow these steps to backport a change into a release branch in compliance with the [commit policy](https://nixos.org/nixpkgs/manual/#submitting-changes-stable-release-branches).
 
-1. Take note of the commit in which the change was introduced into `master`.
+1. Take note of the commits in which the change was introduced into `master` branch.
 2. Check out the target _release branch_, e.g. `release-20.03`. Do not use a _channel branch_ like `nixos-20.03` or `nixpkgs-20.03`.
-3. Use `git cherry-pick -x <original commit>`.
-4. Open your backport PR. Make sure to select the release branch (e.g. `release-20.03`) as the target branch of the PR, and link to the PR in which the original change was made to `master`.
+3. Create a branch for your change, e.g. `git checkout -b backport`.
+4. When the reason to backport is not obvious from the original commit message, use `git cherry-pick -xe <original commit>` and add a reason. Otherwise use `git cherry-pick -x <original commit>`. That's fine for minor version updates that only include security and bug fixes, commits that fixes an otherwise broken package or similar.
+5. Push to GitHub and open a backport pull request. Make sure to select the release branch (e.g. `release-20.03`) as the target branch of the pull request, and link to the pull request in which the original change was comitted to `master`. The pull request title should be the commit title with the release version as prefix, e.g. `[20.03]`.
 
 ## Reviewing contributions