diff --git a/src/agenda_culturel/migrations/0001_squashed_0150_alter_event_local_image.py b/src/agenda_culturel/migrations/0001_squashed_0150_alter_event_local_image.py
index adbbe77..b869fa5 100644
--- a/src/agenda_culturel/migrations/0001_squashed_0150_alter_event_local_image.py
+++ b/src/agenda_culturel/migrations/0001_squashed_0150_alter_event_local_image.py
@@ -101,8 +101,6 @@ class Migration(migrations.Migration):
             fields=[
                 ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('name', models.CharField(help_text='Category name', max_length=512, verbose_name='Name')),
-                ('alt_name', models.CharField(help_text='Alternative name used with a time period', max_length=512, verbose_name='Alternative Name')),
-                ('codename', models.CharField(help_text='Short name of the category', max_length=3, verbose_name='Short name')),
                 ('color', colorfield.fields.ColorField(blank=True, default=None, help_text='Color used as background for the category', image_field=None, max_length=25, null=True, samples=None, verbose_name='Color')),
             ],
             options={
@@ -173,7 +171,7 @@ class Migration(migrations.Migration):
                 ('image_alt', models.CharField(blank=True, help_text='Alternative text used by screen readers for the image', max_length=1024, null=True, verbose_name='Illustration description')),
                 ('reference_urls', django_better_admin_arrayfield.models.fields.ArrayField(base_field=models.URLField(max_length=512), blank=True, help_text='List of all the urls where this event can be found.', null=True, size=None, verbose_name='URLs')),
                 ('tags', django_better_admin_arrayfield.models.fields.ArrayField(base_field=models.CharField(max_length=64), blank=True, help_text='A list of tags that describe the event.', null=True, size=None, verbose_name='Tags')),
-                ('category', models.ForeignKey(default=1, help_text='Category of the event', null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category')),
+                ('category', models.ForeignKey(default=None, help_text='Category of the event', null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category')),
                 ('uuids', django_better_admin_arrayfield.models.fields.ArrayField(base_field=models.CharField(max_length=512), blank=True, help_text='UUIDs from import to detect duplicated entries.', null=True, size=None, verbose_name='UUIDs')),
                 ('imported_date', models.DateTimeField(blank=True, null=True)),
                 ('possibly_duplicated', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='agenda_culturel.duplicatedevents')),
@@ -225,7 +223,7 @@ class Migration(migrations.Migration):
                 ('browsable_url', models.URLField(blank=True, help_text='URL of the corresponding document that will be shown to visitors.', max_length=1024, null=True, verbose_name='Browsable url')),
                 ('defaultLocation', models.CharField(blank=True, help_text='Address for each imported event', max_length=512, null=True, verbose_name='Location')),
                 ('defaultTags', django_better_admin_arrayfield.models.fields.ArrayField(base_field=models.CharField(max_length=64), blank=True, help_text='A list of tags that describe each imported event.', null=True, size=None, verbose_name='Tags for each imported event')),
-                ('defaultCategory', models.ForeignKey(default=1, help_text='Category of each imported event', on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category')),
+                ('defaultCategory', models.ForeignKey(blank=True, default=None, help_text='Category of each imported event', on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category')),
                 ('downloader', models.CharField(choices=[('simple', 'simple'), ('chromium headless', 'Headless Chromium')], default='simple', max_length=20, verbose_name='Downloader')),
                 ('defaultPublished', models.BooleanField(default=True, help_text='Status of each imported event (published or draft)', verbose_name='Published')),
                 ('name', models.CharField(default='', help_text='Recurrent import name', max_length=512, verbose_name='Name')),
@@ -488,41 +486,11 @@ class Migration(migrations.Migration):
             name='pictogram',
             field=models.FileField(blank=True, help_text='Pictogram of the category (svg format)', max_length=1024, null=True, upload_to='', verbose_name='Pictogram'),
         ),
-        migrations.AlterField(
-            model_name='event',
-            name='category',
-            field=models.ForeignKey(default=None, help_text='Category of the event', null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
-        migrations.AlterField(
-            model_name='recurrentimport',
-            name='defaultCategory',
-            field=models.ForeignKey(default=None, help_text='Category of each imported event', on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
-        migrations.AlterField(
-            model_name='event',
-            name='category',
-            field=models.ForeignKey(default=1, help_text='Category of the event', null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
-        migrations.AlterField(
-            model_name='recurrentimport',
-            name='defaultCategory',
-            field=models.ForeignKey(default=1, help_text='Category of each imported event', on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
         migrations.AddField(
             model_name='category',
             name='position',
             field=models.IntegerField(default=0, verbose_name='Position for ordering categories'),
         ),
-        migrations.AlterField(
-            model_name='event',
-            name='category',
-            field=models.ForeignKey(default=1, help_text='Category of the event', null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
-        migrations.AlterField(
-            model_name='recurrentimport',
-            name='defaultCategory',
-            field=models.ForeignKey(default=1, help_text='Category of each imported event', on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
         migrations.AddField(
             model_name='message',
             name='spam',
@@ -547,16 +515,6 @@ class Migration(migrations.Migration):
             name='location',
             field=location_field.models.spatial.LocationField(default=django.contrib.gis.geos.point.Point(3.08333, 45.783329), srid=4326),
         ),
-        migrations.AlterField(
-            model_name='event',
-            name='category',
-            field=models.ForeignKey(default=None, help_text='Category of the event', null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
-        migrations.AlterField(
-            model_name='recurrentimport',
-            name='defaultCategory',
-            field=models.ForeignKey(default=None, help_text='Category of each imported event', on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
         migrations.AlterField(
             model_name='recurrentimport',
             name='processor',
@@ -575,11 +533,6 @@ class Migration(migrations.Migration):
                 'verbose_name_plural': 'Reference locations',
             },
         ),
-        migrations.AlterField(
-            model_name='recurrentimport',
-            name='defaultCategory',
-            field=models.ForeignKey(blank=True, default=None, help_text='Category of each imported event', null=True, on_delete=django.db.models.deletion.SET_DEFAULT, to='agenda_culturel.category', verbose_name='Category'),
-        ),
         migrations.AlterField(
             model_name='recurrentimport',
             name='processor',
@@ -619,14 +572,6 @@ class Migration(migrations.Migration):
             name='name',
             field=models.CharField(help_text='Tag name', max_length=512, unique=True, verbose_name='Name'),
         ),
-        migrations.RemoveField(
-            model_name='category',
-            name='alt_name',
-        ),
-        migrations.RemoveField(
-            model_name='category',
-            name='codename',
-        ),
         migrations.AddField(
             model_name='tag',
             name='category',
diff --git a/src/agenda_culturel/models.py b/src/agenda_culturel/models.py
index ec0765a..a3c8129 100644
--- a/src/agenda_culturel/models.py
+++ b/src/agenda_culturel/models.py
@@ -95,8 +95,6 @@ class StaticContent(models.Model):
 
 class Category(models.Model):
     default_name = "Sans catégorie"
-    default_alt_name = "Événements non catégorisés"
-    default_codename = "∅"
     default_css_class = "cat-nocat"
     default_color = "#aaaaaa"
 
@@ -163,8 +161,6 @@ class Category(models.Model):
             # if it does not exist, return it
             default, created = Category.objects.get_or_create(
                 name=Category.default_name,
-                alt_name=Category.default_alt_name,
-                codename=Category.default_codename,
                 color=Category.default_color,
             )
             return default