diff --git a/lib/modules/manager/dockerfile/readme.md b/lib/modules/manager/dockerfile/readme.md
index 81a83b76a041c970cbf0493f19bdae847dab4e7a..034e0bcba1242c8bbc3daa023333110c80d2173f 100644
--- a/lib/modules/manager/dockerfile/readme.md
+++ b/lib/modules/manager/dockerfile/readme.md
@@ -1,3 +1,22 @@
 Extracts all Docker images in a `Dockerfile`.
 
-If you need to change the versioning format, read the [versioning](https://docs.renovatebot.com/modules/versioning/) documentation to learn more.
+If Renovate does not update your Dockerfile images correctly, you may need to tell Renovate what versioning it should use.
+For example, if you know that an image follows SemVer, you can tell Renovate to use `"semver"` versioning for that image:
+
+```json
+{
+  "packageRules": [
+    {
+      "matchDatasources": ["docker"],
+      "matchPackageNames": ["whitesource/renovate"],
+      "versioning": "semver"
+    }
+  ]
+}
+```
+
+Read [Renovate's Docker Versioning](https://docs.renovatebot.com/modules/versioning/#docker-versioning) docs to learn more.
+
+Renovate's managers does not understand versioning, that's up to Renovate's versioning modules.
+The default Docker versioning for Docker datasources treats suffixes as "compatibility", for example: `-alpine`.
+Many Docker images are _not_ SemVer compliant because they use such suffixes in their tags.