Document usage on self-managed

.gitlab/README.md.template

@@ -149,6 +149,27 @@ However, we cannot use the alternative `+` which would indicate build metadata
 as we'd like.
 See https://github.com/distribution/distribution/issues/1201*
 
+## Usage on self-managed
+
+GitLab CI/CD components are not yet distributed and available on self-managed GitLab instances.
+(see details [here](https://gitlab.com/gitlab-org/gitlab/-/issues/415638)).
+It's also not possible to just include CI/CD components across instance, thus an include like
+`- component: gitlab.com/components/opentofu/full-pipeline@~latest` won't work from a
+self-managed instance.
+However, you could mirror this project from GitLab.com onto any self-managed instance using 
+a [repository pull mirror](https://docs.gitlab.com/ee/user/project/repository/mirror/pull.html).
+and then use the component as you would from GitLab.com, but change the domain, like so:
+
+```yaml
+include:
+  - component: gitlab.example.com/components/opentofu/full-pipeline@~latest
+    inputs:
+      ...
+```
+
+This example assumes your GitLab instance is hosted on `gitlab.example.com` and this component
+project is mirrored in the `components/opentofu` project.
+
 ## Contributing
 
 See the [CONTRIBUTING.md](CONTRIBUTING.md) guide.

README.md

@@ -168,6 +168,27 @@ However, we cannot use the alternative `+` which would indicate build metadata
 as we'd like.
 See https://github.com/distribution/distribution/issues/1201*
 
+## Usage on self-managed
+
+GitLab CI/CD components are not yet distributed and available on self-managed GitLab instances.
+(see details [here](https://gitlab.com/gitlab-org/gitlab/-/issues/415638)).
+It's also not possible to just include CI/CD components across instance, thus an include like
+`- component: gitlab.com/components/opentofu/full-pipeline@~latest` won't work from a
+self-managed instance.
+However, you could mirror this project from GitLab.com onto any self-managed instance using 
+a [repository pull mirror](https://docs.gitlab.com/ee/user/project/repository/mirror/pull.html).
+and then use the component as you would from GitLab.com, but change the domain, like so:
+
+```yaml
+include:
+  - component: gitlab.example.com/components/opentofu/full-pipeline@~latest
+    inputs:
+      ...
+```
+
+This example assumes your GitLab instance is hosted on `gitlab.example.com` and this component
+project is mirrored in the `components/opentofu` project.
+
 ## Contributing
 
 See the [CONTRIBUTING.md](CONTRIBUTING.md) guide.