diff --git a/README.md b/README.md
index b9efae3e..e230c614 100644
--- a/README.md
+++ b/README.md
@@ -49,12 +49,12 @@ Several status are defined:
 
 <ins>Clusters</ins> to replace several markers, depending on the map zoom level.
 Markers are clusterized:
-- by layer (2 markers from 2 different layers will not be clusterized together). Layers can be optionnally qualified by an HTML **content**, for cluster to display it in a tab, in *large* or *normal* **type**, and in its popup.
-- using **status** attribute for the color repartition on cluster, and information displayed in the cluster popup.
+- by layer (2 markers from 2 different layers will not be clusterized together). Layers can be optionnally qualified by an HTML **content**, for cluster to display it in a tab, in *large* or *normal* **type**, and in its popup, where **popupColNumber** allows to display labels in 1 (default) or several columns.
+- using **status** attribute for the colored repartition on cluster, and for information displayed in the cluster popup: **bullet**, **singular** and **plural** labels, and **url** to be called and opened in **urlTarget**, when clicking on a label.
 
-Automatic clustering (engined by Leaflet) can be used to manage up to 100 000 markers. Beyond that, *external* mode allows to manage manually clusters.
+Automatic clustering (engined by Leaflet) can be used to manage up to 100 000 markers. Beyond that, *external* mode allows to manage manually clusters, by building clusters with all attributs described above.
 
-<img src="doc/clusters.png"><img src="doc/clusters_tabs.png">
+<img src="doc/clusters.png"><img src="doc/clusters_tabs.png" width=420>
 
 <ins>User marker</ins> to display the current location of the application user, with an optionnal **direction** (in degree) and **accuracy**.
 
diff --git a/doc/clusters_tabs.png b/doc/clusters_tabs.png
index 88bddd6a..c12f8874 100644
Binary files a/doc/clusters_tabs.png and b/doc/clusters_tabs.png differ