diff --git a/docs/building/pl-fe.md b/docs/building/pl-fe.md
index c8f8cfc80..374a2676f 100644
--- a/docs/building/pl-fe.md
+++ b/docs/building/pl-fe.md
@@ -22,4 +22,9 @@ pnpm -F pl-api build
 pnpm -F pl-fe build
 ```
 
-The built files will be located in the `packages/pl-fe/dist` directory. You can [serve them using a static web server](./installing/standalone.md).
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+The built files will be located in the `packages/pl-fe/dist` directory. You can [serve them using a static web server](./installing/standalone.md).
+
+Following environment variables can be used to customize the instance in build process:
+- `BACKEND_URL` - URL of the Mastodon-compatible instance to connect to. If not set, tries fetching /api/v1/instance from the origin and falls back to standalone mode.
+- `FE_SUBDIRECTORY` - The path where pl-fe is mounted to. Defaults to `/`.
+- `WITH_LANDING_PAGE` - Displays the landing page on the home page, when running in standalone mode.
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