diff --git a/ontology/admin.py b/ontology/admin.py
index 644a51dc6b594812305ea846fab604787c46d309..8583454a507c6a9f18b094847da725fa4ef1b1ab 100644
--- a/ontology/admin.py
+++ b/ontology/admin.py
@@ -4,7 +4,17 @@ __license__ = "AGPL v3"
from django.contrib import admin
-from .models import Tag, Topic, RelationAsym, RelationSym
+from .models import (
+ Branch, AcademicField, Specialty,
+ Tag, Topic, RelationAsym, RelationSym
+)
+
+
+admin.site.register(Branch)
+
+admin.site.register(AcademicField)
+
+admin.site.register(Specialty)
class TagAdmin(admin.ModelAdmin):
diff --git a/ontology/migrations/0006_auto_20200905_1539.py b/ontology/migrations/0006_auto_20200905_1539.py
new file mode 100644
index 0000000000000000000000000000000000000000..9bdd0a630fcbbd2679562e6ad276c10b11e0a0bf
--- /dev/null
+++ b/ontology/migrations/0006_auto_20200905_1539.py
@@ -0,0 +1,66 @@
+# Generated by Django 2.2.11 on 2020-09-05 13:39
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ('ontology', '0005_auto_20181028_2038'),
+ ]
+
+ operations = [
+ migrations.CreateModel(
+ name='AcademicField',
+ fields=[
+ ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+ ('name', models.CharField(max_length=128)),
+ ('slug', models.SlugField(allow_unicode=True, unique=True)),
+ ('order', models.PositiveSmallIntegerField(unique=True)),
+ ],
+ options={
+ 'ordering': ['branch', 'order'],
+ },
+ ),
+ migrations.CreateModel(
+ name='Branch',
+ fields=[
+ ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+ ('name', models.CharField(max_length=128)),
+ ('slug', models.SlugField(allow_unicode=True, unique=True)),
+ ('order', models.PositiveSmallIntegerField(unique=True)),
+ ],
+ options={
+ 'verbose_name_plural': 'branches',
+ 'ordering': ['order'],
+ },
+ ),
+ migrations.CreateModel(
+ name='Specialty',
+ fields=[
+ ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+ ('name', models.CharField(max_length=128)),
+ ('slug', models.SlugField(allow_unicode=True, unique=True)),
+ ('order', models.PositiveSmallIntegerField(unique=True)),
+ ('acad_field', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='specialties', to='ontology.AcademicField')),
+ ],
+ options={
+ 'verbose_name_plural': 'specialties',
+ 'ordering': ['acad_field', 'order'],
+ },
+ ),
+ migrations.AddField(
+ model_name='academicfield',
+ name='branch',
+ field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='academic_fields', to='ontology.Branch'),
+ ),
+ migrations.AddConstraint(
+ model_name='specialty',
+ constraint=models.UniqueConstraint(fields=('acad_field', 'order'), name='unique_acad_field_order'),
+ ),
+ migrations.AddConstraint(
+ model_name='academicfield',
+ constraint=models.UniqueConstraint(fields=('branch', 'order'), name='unique_branch_order'),
+ ),
+ ]
diff --git a/ontology/models/__init__.py b/ontology/models/__init__.py
index 46201bd62ec45e60d74b3875b62a41e3df804dc5..eed5c6d0331abb2d789bbd33665920e42fb421c0 100644
--- a/ontology/models/__init__.py
+++ b/ontology/models/__init__.py
@@ -2,6 +2,12 @@ __copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
__license__ = "AGPL v3"
+from .branch import Branch
+
+from .academic_field import AcademicField
+
+from .specialty import Specialty
+
from .relations import RelationAsym, RelationSym
from .tag import Tag
diff --git a/ontology/models/academic_field.py b/ontology/models/academic_field.py
new file mode 100644
index 0000000000000000000000000000000000000000..b372d59e458e98067ec18acda94c7c100c33733b
--- /dev/null
+++ b/ontology/models/academic_field.py
@@ -0,0 +1,45 @@
+_copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
+__license__ = "AGPL v3"
+
+
+from django.db import models
+
+
+class AcademicField(models.Model):
+ """
+ A principal division of a branch of knowledge.
+ """
+
+ branch = models.ForeignKey(
+ 'ontology.Branch',
+ on_delete=models.CASCADE,
+ related_name='academic_fields'
+ )
+
+ name = models.CharField(
+ max_length=128
+ )
+
+ slug = models.SlugField(
+ unique=True,
+ allow_unicode=True
+ )
+
+ order = models.PositiveSmallIntegerField(
+ unique=True
+ )
+
+ class Meta:
+ constraints = [
+ models.UniqueConstraint(
+ fields=['branch', 'order'],
+ name='unique_branch_order'
+ ),
+ ]
+ ordering = [
+ 'branch',
+ 'order',
+ ]
+
+ def __str__(self):
+ return self.name
diff --git a/ontology/models/branch.py b/ontology/models/branch.py
new file mode 100644
index 0000000000000000000000000000000000000000..056ef74387bce1857b50f6fc23ea82c3c043bf2f
--- /dev/null
+++ b/ontology/models/branch.py
@@ -0,0 +1,33 @@
+_copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
+__license__ = "AGPL v3"
+
+
+from django.db import models
+
+
+class Branch(models.Model):
+ """
+ A principal division in the tree of knowledge.
+ """
+
+ name = models.CharField(
+ max_length=128
+ )
+
+ slug = models.SlugField(
+ unique=True,
+ allow_unicode=True
+ )
+
+ order = models.PositiveSmallIntegerField(
+ unique=True
+ )
+
+ class Meta:
+ ordering = [
+ 'order',
+ ]
+ verbose_name_plural = 'branches'
+
+ def __str__(self):
+ return self.name
diff --git a/ontology/models/specialty.py b/ontology/models/specialty.py
new file mode 100644
index 0000000000000000000000000000000000000000..865cc195b9d9a4de24c95c1a13409ac194b93eca
--- /dev/null
+++ b/ontology/models/specialty.py
@@ -0,0 +1,46 @@
+_copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
+__license__ = "AGPL v3"
+
+
+from django.db import models
+
+
+class Specialty(models.Model):
+ """
+ A principal division of an AcademicField.
+ """
+
+ acad_field = models.ForeignKey(
+ 'ontology.AcademicField',
+ on_delete=models.CASCADE,
+ related_name='specialties'
+ )
+
+ name = models.CharField(
+ max_length=128
+ )
+
+ slug = models.SlugField(
+ unique=True,
+ allow_unicode=True
+ )
+
+ order = models.PositiveSmallIntegerField(
+ unique=True
+ )
+
+ class Meta:
+ constraints = [
+ models.UniqueConstraint(
+ fields=['acad_field', 'order'],
+ name='unique_acad_field_order'
+ ),
+ ]
+ ordering = [
+ 'acad_field',
+ 'order',
+ ]
+ verbose_name_plural = 'specialties'
+
+ def __str__(self):
+ return self.name