diff --git a/docs/usage/configuration-options.md b/docs/usage/configuration-options.md
index 5d2a7c5f43592e2117b28ed512598dd1b1c4c86b..92370405f3bf70f7fc3dd50c643d0270be2095bd 100644
--- a/docs/usage/configuration-options.md
+++ b/docs/usage/configuration-options.md
@@ -1416,7 +1416,20 @@ If the `versioning` for a dependency is not captured with a named group then it
 
 ## registryUrls
 
-This is only necessary in case you need to manually configure a registry URL to use for datasource lookups. Applies to PyPI (pip) only for now. Supports only one URL for now but is defined as a list for forward compatibility.
+Usually Renovate is able to either (a) use the default registries for a datasource, or (b) automatically detect during the manager extract phase which custom registries are in use. In case there is a need to configure them manually, it can be done using this `registryUrls` field, typically using `packageUrls` like so:
+
+```json
+{
+  "packageRules": [
+    {
+      "datasources": ["docker"],
+      "registryUrls": ["https://docker.mycompany.domain"]
+    }
+  ]
+}
+```
+
+The field supports multiple URLs however it is datasource-dependent on whether only the first is used or multiple.
 
 ## requiredStatusChecks