diff --git a/apis_ontology/migrations/0044_expression_notes.py b/apis_ontology/migrations/0044_expression_notes.py
new file mode 100644
index 0000000..6749f39
--- /dev/null
+++ b/apis_ontology/migrations/0044_expression_notes.py
@@ -0,0 +1,23 @@
+# Generated by Django 4.2.11 on 2024-03-25 08:05
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("apis_ontology", "0043_rename_first_name_character_forename_and_more"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="expression",
+            name="notes",
+            field=models.TextField(
+                blank=True,
+                default="",
+                help_text="Feld für interne Notizen",
+                max_length=1024,
+                verbose_name="Notiz",
+            ),
+        ),
+    ]
diff --git a/apis_ontology/models.py b/apis_ontology/models.py
index 9f8c7e9..9d844cc 100644
--- a/apis_ontology/models.py
+++ b/apis_ontology/models.py
@@ -35,6 +35,23 @@ class Meta:
         verbose_name_plural = _("progress states")
 
 
+class NotesMixin(models.Model):
+    """
+    Mixin for internal notes.
+    """
+
+    notes = models.TextField(
+        max_length=1024,
+        blank=True,
+        default="",
+        verbose_name=_("Notiz"),
+        help_text=_("Feld für interne Notizen"),
+    )
+
+    class Meta:
+        abstract = True
+
+
 @reversion.register
 class AlternativeNameMixin(models.Model):
     """
@@ -490,7 +507,9 @@ class Meta:
 
 
 @reversion.register(follow=["rootobject_ptr"])
-class Expression(TitlesMixin, DescriptionMixin, StatusMixin, AbstractEntity):
+class Expression(
+    TitlesMixin, DescriptionMixin, NotesMixin, StatusMixin, AbstractEntity
+):
     """
     A concrete representation of a given Work,
     captured in signs, images, audio signals,...