diff --git a/README.md b/README.md
index 5ce4a23..5bf374b 100644
--- a/README.md
+++ b/README.md
@@ -4,3 +4,7 @@
 [![Microbadger](https://images.microbadger.com/badges/image/xoxys/nginx.svg)](https://microbadger.com/images/xoxys/nginx "Get your own image badge on microbadger.com")
 
 Rootless nginx base image based on Alpine.
+
+Currently, there are no options to overwrite through environment variables but you can use `FROM: xoxys/nginx:latest` to build a custom image.
+
+The pre-configured non-root user is a system user named `nginx` with the UID `101`. There is also a primary group with the same values.