diff --git a/README.md b/README.md
index fe23f12..80de938 100644
--- a/README.md
+++ b/README.md
@@ -380,21 +380,23 @@ After first success you have to replace `--issue` with `--renew`.
 
 # Configuration
 
-| Variable               | Default                                | Usage                                                                                                |
-|------------------------|----------------------------------------|------------------------------------------------------------------------------------------------------|
-| `DEBUG`                | `false`                                | Toggles `fastapi` debug mode                                                                         |
-| `DLS_URL`              | `localhost`                            | Used in client-token to tell guest driver where dls instance is reachable                            |
-| `DLS_PORT`             | `443`                                  | Used in client-token to tell guest driver where dls instance is reachable                            |
-| `TOKEN_EXPIRE_DAYS`    | `1`                                    | Client auth-token validity (used for authenticate client against api, **not `.tok` file!**)          |
-| `LEASE_EXPIRE_DAYS`    | `90`                                   | Lease time in days                                                                                   |
-| `LEASE_RENEWAL_PERIOD` | `0.15`                                 | The percentage of the lease period that must elapse before a licensed client can renew a license \*1 |
-| `DATABASE`             | `sqlite:///db.sqlite`                  | See [official SQLAlchemy docs](https://docs.sqlalchemy.org/en/14/core/engines.html)                  |
-| `CORS_ORIGINS`         | `https://{DLS_URL}`                    | Sets `Access-Control-Allow-Origin` header (comma separated string) \*2                               |
-| `SITE_KEY_XID`         | `00000000-0000-0000-0000-000000000000` | Site identification uuid                                                                             |
-| `INSTANCE_REF`         | `10000000-0000-0000-0000-000000000001` | Instance identification uuid                                                                         |
-| `ALLOTMENT_REF`        | `20000000-0000-0000-0000-000000000001` | Allotment identification uuid                                                                        |
-| `INSTANCE_KEY_RSA`     | `<app-dir>/cert/instance.private.pem`  | Site-wide private RSA key for singing JWTs \*3                                                       |
-| `INSTANCE_KEY_PUB`     | `<app-dir>/cert/instance.public.pem`   | Site-wide public key \*3                                                                             |
+| Variable               | Default                                | Usage                                                                                                              |
+|------------------------|----------------------------------------|--------------------------------------------------------------------------------------------------------------------|
+| `DEBUG`                | `false`                                | Toggles `fastapi` debug mode                                                                                       |
+| `DLS_URL`              | `localhost`                            | Used in client-token to tell guest driver where dls instance is reachable                                          |
+| `DLS_PORT`             | `443`                                  | Used in client-token to tell guest driver where dls instance is reachable                                          |
+| `HA_REPLICATE`         |                                        | `DLS_URL` + `DLS_PORT` of primary DLS instance, e.g. `dls-node:443` (for HA only **two** nodes are supported!) \*1 |
+| `HA_ROLE`              |                                        | `PRIMARY` or `SECONDARY`                                                                                           |
+| `TOKEN_EXPIRE_DAYS`    | `1`                                    | Client auth-token validity (used for authenticate client against api, **not `.tok` file!**)                        |
+| `LEASE_EXPIRE_DAYS`    | `90`                                   | Lease time in days                                                                                                 |
+| `LEASE_RENEWAL_PERIOD` | `0.15`                                 | The percentage of the lease period that must elapse before a licensed client can renew a license \*2               |
+| `DATABASE`             | `sqlite:///db.sqlite`                  | See [official SQLAlchemy docs](https://docs.sqlalchemy.org/en/14/core/engines.html)                                |
+| `CORS_ORIGINS`         | `https://{DLS_URL}`                    | Sets `Access-Control-Allow-Origin` header (comma separated string) \*3                                             |
+| `SITE_KEY_XID`         | `00000000-0000-0000-0000-000000000000` | Site identification uuid                                                                                           |
+| `INSTANCE_REF`         | `10000000-0000-0000-0000-000000000001` | Instance identification uuid                                                                                       |
+| `ALLOTMENT_REF`        | `20000000-0000-0000-0000-000000000001` | Allotment identification uuid                                                                                      |
+| `INSTANCE_KEY_RSA`     | `<app-dir>/cert/instance.private.pem`  | Site-wide private RSA key for singing JWTs \*4                                                                     |
+| `INSTANCE_KEY_PUB`     | `<app-dir>/cert/instance.public.pem`   | Site-wide public key \*4                                                                                           |
 
 \*1 If you want to use HA, this value should be point to `secondary` on `primary` and `primary` on `secondary`. Don't
 use same database for both instances!