diff --git a/README.md b/README.md
index 1a312d5..b47d119 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ defined competence aspects.
 * [API documentation](http://dcm.bitplan.com/docs)
 
 ### Model
-![Class Diagram](http://www.plantuml.com/plantuml/proxy?src=https://raw.githubusercontent.com/WolfgangFahl/dcm/main/dcm.puml?fmt=svg&version=4)
+![Class Diagram](http://www.plantuml.com/plantuml/proxy?src=https://raw.githubusercontent.com/WolfgangFahl/dcm/main/dcm.puml?fmt=svg&version=5)
 
 ## Authors
 * [Wolfgang Fahl](http://www.bitplan.com/Wolfgang_Fahl)
diff --git a/dcm.puml b/dcm.puml
index fde9d9d..f9e909c 100644
--- a/dcm.puml
+++ b/dcm.puml
@@ -41,6 +41,7 @@ class dcm.dcm_core.CompetenceFacet {
 class dcm.dcm_core.CompetenceLevel {
   level: int
   icon: str
+  utf8_icon: str
 }
 
 class dcm.dcm_core.CompetenceTree {
diff --git a/dcm/dcm_assessment.py b/dcm/dcm_assessment.py
index c7f5670..4b3af3a 100644
--- a/dcm/dcm_assessment.py
+++ b/dcm/dcm_assessment.py
@@ -51,8 +51,12 @@ def setup_buttons(self):
         self.buttons = {}
         with ui.row() as self.row:
             for level in self.competence_tree.levels:
+                # generate a button to represent the level
+                button_label=level.name
+                if level.utf8_icon:
+                    button_label=f"{level.utf8_icon} {level.name}"
                 button = ui.button(
-                    level.name,
+                    button_label,
                     icon=level.icon,
                     color=level.color_code,
                     on_click=lambda _args, l=level.level: self.handle_selection(l),