diff --git a/README.md b/README.md
index 09a563c..f856159 100644
To iterate quickly, it's easier to make changes directly in the browser tooling and then bring the changes over to the CSS files after the fact.
+## CAMEL_ENV environment variable
+Setting the `CAMEL_ENV` changes the output of the website build slightly, possible values are `development` (set by default if `CAMEL_ENV` is unset), `production` or `netlify`.
+To run the optimizations, which currently consist of running [htmlmin](https://kangax.github.io/html-minifier/) to reduce the size of generated HTML documents, set the `CAMEL_ENV` environment variable to `production`, for example:
+ $ CAMEL_ENV=production yarn build
+When build is performed on Netlify, we set it to `netlify` to add the link to Netlify required by Netlify's open source policy.
## Contribute changes
The Apache Camel website is composed of different sources. So where to add and contribute changes in particular?