diff --git a/docs/maintainers/handbook.md b/docs/maintainers/handbook.md
index dcbf896..4bbef5f 100644
--- a/docs/maintainers/handbook.md
+++ b/docs/maintainers/handbook.md
@@ -530,3 +530,11 @@ archive, tooling will unzip files in the archive back to those paths.
 
 In the case of restoring database tables, you can use the `pre-hook` &
 `post-hook` commands to run the insertion logic.
+
+## Can I override a service within a recipe?
+
+You can use [this `docker-compose` trick](https://docs.docker.com/compose/extends/#understanding-multiple-compose-files) to do this.
+
+If you have a recipe that is using a `mysql` service and you'd like to use `postgresql` instead, you can create a `compose.psql.yml`!
+
+An example of this is the [`selfoss`](https://git.coopcloud.tech/coop-cloud/selfoss) recipe. The default is `sqlite` but there is a `postgresql` compose configuration there too.