diff --git a/src/libcamera/control_ids_core.yaml b/src/libcamera/control_ids_core.yaml
index 89991d03d7..acd8ffd85a 100644
--- a/src/libcamera/control_ids_core.yaml
+++ b/src/libcamera/control_ids_core.yaml
@@ -188,6 +188,25 @@ controls:
         - name: ExposureCustom
           value: 3
           description: Custom exposure mode.
+        - name: ExposureMaximize
+          value: 4
+          description: |
+            Exposure mode allowing very large exposure times and gains.
+
+            This mode is intended to make the full capabilities of the sensor
+            available. In practice this allows multi-second exposures and
+            maximum available analogue gain. In contrast to other modes,
+            it is generally expected that the exposure time is maximized first,
+            and only then is gain used to achieve the target exposure. Note,
+            that this mode can be customized in tuning files, thus the behaviour
+            might differ slightly.
+
+            Such behaviour can be useful for mostly static scenes where the
+            lighting changes drastically over a period of time (e.g. capturing
+            the sky 24 hours a day).
+
+            Be aware that FrameDurationLimits will always apply, potentially reducing
+            the maximum achievable exposure time.
 
   - ExposureValue:
       type: float