diff --git a/src/tixlbase/cache.py b/src/tixlbase/cache.py
index c84369b25..f6099d4b3 100644
--- a/src/tixlbase/cache.py
+++ b/src/tixlbase/cache.py
@@ -15,8 +15,9 @@ class EventRelatedCache:
     main purpose of this is to be able to flush all cached data related
     to this event at once.
 
-    The object is stateless, all state is in the cache, so you can
-    instantiate it as many times as you want.
+    The EventRelatedCache instance itself is stateless, all state is
+    stored in the cache backend, so you can instantiate this class as many
+    times as you want.
     """
 
     def __init__(self, event: Event, cache: str='default'):
diff --git a/src/tixlbase/forms.py b/src/tixlbase/forms.py
index ae46dc43d..3b661dc4e 100644
--- a/src/tixlbase/forms.py
+++ b/src/tixlbase/forms.py
@@ -4,6 +4,9 @@ from versions.models import Versionable
 
 
 class VersionedBaseModelForm(BaseModelForm):
+    """
+    This is a helperclass to construct VersionedModelForm
+    """
     def save(self, commit=True):
         if self.instance.pk is not None and isinstance(self.instance, Versionable):
             if self.has_changed():
@@ -12,4 +15,11 @@ class VersionedBaseModelForm(BaseModelForm):
 
 
 class VersionedModelForm(six.with_metaclass(ModelFormMetaclass, VersionedBaseModelForm)):
+    """
+    This is a modified version of Django's ModelForm which differs from ModelForm in
+    only one way: It executes the .clone() method of an object before saving it back to
+    the database, if the model is a sub-class of versions.models.Versionable. You can
+    safely use this as a base class for all your model forms, it will work out correctly
+    with both versioned and non-versioned models.
+    """
     pass
diff --git a/src/tixlbase/models.py b/src/tixlbase/models.py
index b09b570d9..37c74278d 100644
--- a/src/tixlbase/models.py
+++ b/src/tixlbase/models.py
@@ -349,7 +349,8 @@ class EventPermission(Versionable):
 
 class ItemCategory(Versionable):
     """
-    Items can be sorted into categories
+    Items can be sorted into categories, which only have a name and a
+    configurable order
     """
     event = VersionedForeignKey(
         Event,
@@ -385,9 +386,8 @@ class ItemCategory(Versionable):
 
 class Property(Versionable):
     """
-    A property is a modifier which can be applied to an
-    Item. For example 'Size' would be a property associated
-    with the item 'T-Shirt'.
+    A property is a modifier which can be applied to an Item. For example
+    'Size' would be a property associated with the item 'T-Shirt'.
     """
 
     event = VersionedForeignKey(
diff --git a/src/tixlbase/plugins.py b/src/tixlbase/plugins.py
index ffe7856fd..a1814fffa 100644
--- a/src/tixlbase/plugins.py
+++ b/src/tixlbase/plugins.py
@@ -1,7 +1,7 @@
 try:  # NOQA
     from enum import Enum
 except ImportError:  # NOQA
-    from flufl.enum import Enum
+    from flufl.enum import Enum  # remove this dependency when support for python <=3.3 is dropped
 
 from django.apps import apps
 
@@ -10,7 +10,10 @@ class PluginType(Enum):
     RESTRICTION = 1
 
 
-def get_all_plugins() -> "class":
+def get_all_plugins() -> "List[class]":
+    """
+    Returns the TixlPluginMeta classes of all plugins found in the installed Django apps.
+    """
     plugins = []
     for app in apps.get_app_configs():
         if hasattr(app, 'TixlPluginMeta'):
diff --git a/src/tixlbase/signals.py b/src/tixlbase/signals.py
index cccaaa92e..36603fdd4 100644
--- a/src/tixlbase/signals.py
+++ b/src/tixlbase/signals.py
@@ -4,6 +4,11 @@ from django.dispatch.dispatcher import NO_RECEIVERS
 
 
 class EventPluginSignal(django.dispatch.Signal):
+    """
+    This is an extension to Django's built-in signals which differs in a way that it sends
+    out it's events only to receivers which belong to plugins that are enabled for the given
+    Event.
+    """
 
     def send(self, sender, **named):
         """
@@ -34,6 +39,11 @@ class EventPluginSignal(django.dispatch.Signal):
                 responses.append((receiver, response))
         return responses
 
+"""
+This signal is sent out every time some component of tixl wants to know whether a specific
+item or variation is available for sell. The item will only be sold, if all (active) receivers
+return a positive result (see plugin API documentation for details).
+"""
 determine_availability = EventPluginSignal(
     providing_args=["item", "variations", "context", "cache"]
 )
diff --git a/src/tixlbase/views.py b/src/tixlbase/views.py
deleted file mode 100644
index e69de29bb..000000000
diff --git a/src/tixlcontrol/admin.py b/src/tixlcontrol/admin.py
deleted file mode 100644
index 8c38f3f3d..000000000
--- a/src/tixlcontrol/admin.py
+++ /dev/null
@@ -1,3 +0,0 @@
-from django.contrib import admin
-
-# Register your models here.
diff --git a/src/tixlcontrol/context.py b/src/tixlcontrol/context.py
index 3970ac98d..6c4d7b569 100644
--- a/src/tixlcontrol/context.py
+++ b/src/tixlcontrol/context.py
@@ -3,6 +3,9 @@ from django.core.urlresolvers import resolve
 
 
 def contextprocessor(request):
+    """
+    Adds data to all template contexts
+    """
     ctx = {
         'url_name': resolve(request.path_info).url_name,
         'settings': settings,
diff --git a/src/tixlcontrol/middleware.py b/src/tixlcontrol/middleware.py
index b38fa2fd5..d124a7bd7 100644
--- a/src/tixlcontrol/middleware.py
+++ b/src/tixlcontrol/middleware.py
@@ -13,8 +13,7 @@ from tixlbase.models import Event
 class PermissionMiddleware:
 
     """
-    This middleware enforces all requests to the control app
-    to require login.
+    This middleware enforces all requests to the control app to require login.
     Additionally, it enforces all requests to "control:event." URLs
     to be for an event the user has basic access to.
     """
@@ -56,4 +55,5 @@ class PermissionMiddleware:
                     organizer__slug=url.kwargs['organizer'],
                 )
             except Event.DoesNotExist:
-                return HttpResponseNotFound(_("The selected event was not found or you have no permission to administrate it."))
+                return HttpResponseNotFound(_("The selected event was not found or you "
+                                              "have no permission to administrate it."))
diff --git a/src/tixlcontrol/permissions.py b/src/tixlcontrol/permissions.py
index 64d1b0b3b..7b1f9a7c2 100644
--- a/src/tixlcontrol/permissions.py
+++ b/src/tixlcontrol/permissions.py
@@ -5,6 +5,10 @@ from tixlbase.models import EventPermission
 
 
 def event_permission_required(permission):
+    """
+    This view decorator rejects all requests with a 403 response which are not from
+    users having the given permission for the event the request is associated with.
+    """
     def decorator(function):
         def wrapper(request, *args, **kw):
             if not request.user.is_authenticated():
@@ -26,6 +30,10 @@ def event_permission_required(permission):
 
 
 class EventPermissionRequiredMixin:
+    """
+    This mixin is equivalent to the event_permission_required view decorator but
+    is in a form suitable for class-based views.
+    """
     permission = ''
 
     @classmethod
diff --git a/src/tixlcontrol/signals.py b/src/tixlcontrol/signals.py
index 2d660d986..7f5d9ff73 100644
--- a/src/tixlcontrol/signals.py
+++ b/src/tixlcontrol/signals.py
@@ -1,6 +1,10 @@
 from tixlbase.signals import EventPluginSignal
 
 
+"""
+This signal is sent out to build configuration forms for all restriction formsets
+(see plugin API documentation for details).
+"""
 restriction_formset = EventPluginSignal(
     providing_args=["item"]
 )
diff --git a/src/tixlcontrol/urls.py b/src/tixlcontrol/urls.py
index a4fd4cd10..ef9395106 100644
--- a/src/tixlcontrol/urls.py
+++ b/src/tixlcontrol/urls.py
@@ -22,21 +22,30 @@ urlpatterns += patterns(
             url(r'^settings/plugins$', event.EventPlugins.as_view(), name='event.settings.plugins'),
             url(r'^items/$', item.ItemList.as_view(), name='event.items'),
             url(r'^items/(?P<item>[0-9a-f-]+)/$', item.ItemUpdateGeneral.as_view(), name='event.item'),
-            url(r'^items/(?P<item>[0-9a-f-]+)/variations$', item.ItemVariations.as_view(), name='event.item.variations'),
-            url(r'^items/(?P<item>[0-9a-f-]+)/restrictions$', item.ItemRestrictions.as_view(), name='event.item.restrictions'),
+            url(r'^items/(?P<item>[0-9a-f-]+)/variations$', item.ItemVariations.as_view(),
+                name='event.item.variations'),
+            url(r'^items/(?P<item>[0-9a-f-]+)/restrictions$', item.ItemRestrictions.as_view(),
+                name='event.item.restrictions'),
             url(r'^categories/$', item.CategoryList.as_view(), name='event.items.categories'),
-            url(r'^categories/(?P<category>[0-9a-f-]+)/delete$', item.CategoryDelete.as_view(), name='event.items.categories.delete'),
+            url(r'^categories/(?P<category>[0-9a-f-]+)/delete$', item.CategoryDelete.as_view(),
+                name='event.items.categories.delete'),
             url(r'^categories/(?P<category>[0-9a-f-]+)/up$', item.category_move_up, name='event.items.categories.up'),
-            url(r'^categories/(?P<category>[0-9a-f-]+)/down$', item.category_move_down, name='event.items.categories.down'),
-            url(r'^categories/(?P<category>[0-9a-f-]+)/$', item.CategoryUpdate.as_view(), name='event.items.categories.edit'),
+            url(r'^categories/(?P<category>[0-9a-f-]+)/down$', item.category_move_down,
+                name='event.items.categories.down'),
+            url(r'^categories/(?P<category>[0-9a-f-]+)/$', item.CategoryUpdate.as_view(),
+                name='event.items.categories.edit'),
             url(r'^categories/add$', item.CategoryCreate.as_view(), name='event.items.categories.add'),
             url(r'^questions/$', item.QuestionList.as_view(), name='event.items.questions'),
-            url(r'^questions/(?P<question>[0-9a-f-]+)/delete$', item.QuestionDelete.as_view(), name='event.items.questions.delete'),
-            url(r'^questions/(?P<question>[0-9a-f-]+)/$', item.QuestionUpdate.as_view(), name='event.items.questions.edit'),
+            url(r'^questions/(?P<question>[0-9a-f-]+)/delete$', item.QuestionDelete.as_view(),
+                name='event.items.questions.delete'),
+            url(r'^questions/(?P<question>[0-9a-f-]+)/$', item.QuestionUpdate.as_view(),
+                name='event.items.questions.edit'),
             url(r'^questions/add$', item.QuestionCreate.as_view(), name='event.items.questions.add'),
             url(r'^properties/$', item.PropertyList.as_view(), name='event.items.properties'),
-            url(r'^properties/(?P<property>[0-9a-f-]+)/$', item.PropertyUpdate.as_view(), name='event.items.properties.edit'),
-            url(r'^properties/(?P<property>[0-9a-f-]+)/delete$', item.PropertyDelete.as_view(), name='event.items.properties.delete'),
+            url(r'^properties/(?P<property>[0-9a-f-]+)/$', item.PropertyUpdate.as_view(),
+                name='event.items.properties.edit'),
+            url(r'^properties/(?P<property>[0-9a-f-]+)/delete$', item.PropertyDelete.as_view(),
+                name='event.items.properties.delete'),
             url(r'^properties/add$', item.PropertyCreate.as_view(), name='event.items.properties.add'),
             url(r'^quotas/$', item.QuotaList.as_view(), name='event.items.quotas'),
             url(r'^quotas/(?P<quota>[0-9a-f-]+)/$', item.QuotaUpdate.as_view(), name='event.items.quotas.edit'),
diff --git a/src/tixlcontrol/views/auth.py b/src/tixlcontrol/views/auth.py
index f66493114..56dcec29e 100644
--- a/src/tixlcontrol/views/auth.py
+++ b/src/tixlcontrol/views/auth.py
@@ -9,8 +9,8 @@ from django.contrib.auth import logout as auth_logout
 
 class AuthenticationForm(BaseAuthenticationForm):
     """
-    The login form, providing an email and password field. The
-    form does already implement validation for correct user data.
+    The login form, providing an email and password field. The form already implements
+    validation for correct user data.
     """
     email = forms.EmailField(label=_("E-mail address"), max_length=254)
     password = forms.CharField(label=_("Password"), widget=forms.PasswordInput)
@@ -68,5 +68,8 @@ def login(request):
 
 
 def logout(request):
+    """
+    Log the user out of the current session, then redirect to login page.
+    """
     auth_logout(request)
     return redirect('control:auth.login')
diff --git a/src/tixlcontrol/views/event.py b/src/tixlcontrol/views/event.py
index 63e7f16f5..289664091 100644
--- a/src/tixlcontrol/views/event.py
+++ b/src/tixlcontrol/views/event.py
@@ -70,7 +70,7 @@ class EventPlugins(EventPermissionRequiredMixin, TemplateView, SingleObjectMixin
     permission = 'can_change_settings'
     template_name = 'tixlcontrol/event/plugins.html'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Event:
         return self.request.event
 
     def get_context_data(self, *args, **kwargs) -> dict:
diff --git a/src/tixlcontrol/views/forms.py b/src/tixlcontrol/views/forms.py
index dd8fb80b4..640d78a58 100644
--- a/src/tixlcontrol/views/forms.py
+++ b/src/tixlcontrol/views/forms.py
@@ -13,6 +13,14 @@ from tixlbase.models import ItemVariation, PropertyValue, Item
 
 
 class TolerantFormsetModelForm(VersionedModelForm):
+    """
+    This is equivalent to a normal VersionedModelForm, but works around a problem that
+    arises when the form is used inside a FormSet with can_order=True and django-formset-js
+    enabled. In this configuration, even empty "extra" forms might have an ORDER value
+    sent and Django marks the form as empty and raises validation errors because the other
+    fields have not been filled.
+    """
+
     def has_changed(self) -> bool:
         """
         Returns True if data differs from initial. Contrary to the default
@@ -99,6 +107,10 @@ class RestrictionInlineFormset(forms.BaseInlineFormSet):
 
 
 class VariationsFieldRenderer(forms.widgets.CheckboxFieldRenderer):
+    """
+    This is the default renderer for a VariationsField. Based on the choice input class
+    this renders a list or a matrix of checkboxes/radio buttons/...
+    """
 
     def __init__(self, name, value, attrs, choices):
         self.name = name
@@ -207,10 +219,17 @@ class VariationsFieldRenderer(forms.widgets.CheckboxFieldRenderer):
 
 
 class VariationsCheckboxRenderer(VariationsFieldRenderer):
+    """
+    This is the same as VariationsFieldRenderer but with the choice input class
+    forced to checkboxes
+    """
     choice_input_class = forms.widgets.CheckboxChoiceInput
 
 
 class VariationsSelectMultiple(forms.CheckboxSelectMultiple):
+    """
+    This is the default widget for a VariationsField
+    """
     renderer = VariationsCheckboxRenderer
     _empty_value = []
 
@@ -240,7 +259,7 @@ class VariationsField(forms.ModelMultipleChoiceField):
         """
         We can't use a normal QuerySet as there theoretically might be
         two types of variations: Some who already have a ItemVariation
-        object associated with tham and some who don't. We therefore use
+        object associated with them and some who don't. We therefore use
         the item's ``get_all_variations`` method. In the first case, we
         use the ItemVariation objects primary key as our choice, key,
         in the latter case we use a string constructed from the values
diff --git a/src/tixlcontrol/views/item.py b/src/tixlcontrol/views/item.py
index 9afb31422..e47a7d637 100644
--- a/src/tixlcontrol/views/item.py
+++ b/src/tixlcontrol/views/item.py
@@ -47,7 +47,7 @@ class CategoryDelete(EventPermissionRequiredMixin, DeleteView):
     permission = 'can_change_items'
     context_object_name = 'category'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> ItemCategory:
         url = resolve(self.request.path_info)
         return self.request.event.categories.current.get(
             identity=url.kwargs['category']
@@ -62,7 +62,7 @@ class CategoryDelete(EventPermissionRequiredMixin, DeleteView):
         self.object.delete()
         return HttpResponseRedirect(success_url)
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.categories', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -76,13 +76,13 @@ class CategoryUpdate(EventPermissionRequiredMixin, UpdateView):
     permission = 'can_change_items'
     context_object_name = 'category'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> ItemCategory:
         url = resolve(self.request.path_info)
         return self.request.event.categories.current.get(
             identity=url.kwargs['category']
         )
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.categories', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -96,7 +96,7 @@ class CategoryCreate(EventPermissionRequiredMixin, CreateView):
     permission = 'can_change_items'
     context_object_name = 'category'
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.categories', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -116,7 +116,12 @@ class CategoryList(ListView):
         return self.request.event.categories.current.all()
 
 
-def category_move(request, organizer, event, category, up=True):
+def category_move(request, category, up=True):
+    """
+    This is a helper function to avoid duplicating code in category_move_up and
+    category_move_down. It takes a category and a direction and then tries to bring
+    all categories for this event in a new order.
+    """
     category = request.event.categories.current.get(
         identity=category
     )
@@ -136,7 +141,7 @@ def category_move(request, organizer, event, category, up=True):
 
 @event_permission_required("can_change_items")
 def category_move_up(request, organizer, event, category):
-    category_move(request, organizer, event, category, up=True)
+    category_move(request, category, up=True)
     return redirect(reverse('control:event.items.categories', kwargs={
         'organizer': request.event.organizer.slug,
         'event': request.event.slug,
@@ -145,7 +150,7 @@ def category_move_up(request, organizer, event, category):
 
 @event_permission_required("can_change_items")
 def category_move_down(request, organizer, event, category):
-    category_move(request, organizer, event, category, up=False)
+    category_move(request, category, up=False)
     return redirect(reverse('control:event.items.categories', kwargs={
         'organizer': request.event.organizer.slug,
         'event': request.event.slug,
@@ -188,13 +193,13 @@ class PropertyUpdate(EventPermissionRequiredMixin, UpdateView):
     permission = 'can_change_items'
     context_object_name = 'property'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Property:
         url = resolve(self.request.path_info)
         return self.request.event.properties.current.get(
             identity=url.kwargs['property']
         )
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         url = resolve(self.request.path_info)
         return reverse('control:event.items.properties.edit', kwargs={
             'organizer': self.request.event.organizer.slug,
@@ -214,7 +219,7 @@ class PropertyUpdate(EventPermissionRequiredMixin, UpdateView):
         formset = formsetclass(**kwargs)
         return formset
 
-    def get_context_data(self, *args, **kwargs):
+    def get_context_data(self, *args, **kwargs) -> dict:
         context = super().get_context_data(*args, **kwargs)
         context['formset'] = self.get_formset()
         return context
@@ -249,7 +254,7 @@ class PropertyCreate(EventPermissionRequiredMixin, CreateView):
     permission = 'can_change_items'
     context_object_name = 'property'
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.properties', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -265,7 +270,7 @@ class PropertyCreate(EventPermissionRequiredMixin, CreateView):
         formset = formsetclass(**self.get_form_kwargs())
         return formset
 
-    def get_context_data(self, *args, **kwargs):
+    def get_context_data(self, *args, **kwargs) -> dict:
         self.object = None
         context = super().get_context_data(*args, **kwargs)
         context['formset'] = self.get_formset()
@@ -297,16 +302,16 @@ class PropertyDelete(EventPermissionRequiredMixin, DeleteView):
     permission = 'can_change_items'
     context_object_name = 'property'
 
-    def get_context_data(self, *args, **kwargs):
+    def get_context_data(self, *args, **kwargs) -> dict:
         context = super().get_context_data(*args, **kwargs)
         context['dependent'] = self.get_object().items.current.all()
         context['possible'] = self.is_allowed()
         return context
 
-    def is_allowed(self):
+    def is_allowed(self) -> bool:
         return self.get_object().items.current.count() == 0
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Property:
         if not hasattr(self, 'object') or not self.object:
             url = resolve(self.request.path_info)
             self.object = self.request.event.properties.current.get(
@@ -322,7 +327,7 @@ class PropertyDelete(EventPermissionRequiredMixin, DeleteView):
         else:
             return HttpResponseForbidden()
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.properties', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -356,13 +361,13 @@ class QuestionDelete(EventPermissionRequiredMixin, DeleteView):
     permission = 'can_change_items'
     context_object_name = 'question'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Question:
         url = resolve(self.request.path_info)
         return self.request.event.questions.current.get(
             identity=url.kwargs['question']
         )
 
-    def get_context_data(self, *args, **kwargs):
+    def get_context_data(self, *args, **kwargs) -> dict:
         context = super().get_context_data(*args, **kwargs)
         context['dependent'] = list(self.get_object().items.current.all())
         return context
@@ -373,7 +378,7 @@ class QuestionDelete(EventPermissionRequiredMixin, DeleteView):
         self.object.delete()
         return HttpResponseRedirect(success_url)
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.questions', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -387,13 +392,13 @@ class QuestionUpdate(EventPermissionRequiredMixin, UpdateView):
     permission = 'can_change_items'
     context_object_name = 'question'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Question:
         url = resolve(self.request.path_info)
         return self.request.event.questions.current.get(
             identity=url.kwargs['question']
         )
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.questions', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -407,7 +412,7 @@ class QuestionCreate(EventPermissionRequiredMixin, CreateView):
     permission = 'can_change_items'
     context_object_name = 'question'
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.questions', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -447,7 +452,7 @@ class QuotaCreate(EventPermissionRequiredMixin, CreateView):
     permission = 'can_change_items'
     context_object_name = 'quota'
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.quotas', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -465,13 +470,13 @@ class QuotaUpdate(EventPermissionRequiredMixin, UpdateView):
     permission = 'can_change_items'
     context_object_name = 'quota'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Quota:
         url = resolve(self.request.path_info)
         return self.request.event.quotas.current.get(
             identity=url.kwargs['quota']
         )
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.quotas', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -484,13 +489,13 @@ class QuotaDelete(EventPermissionRequiredMixin, DeleteView):
     permission = 'can_change_items'
     context_object_name = 'quota'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Quota:
         url = resolve(self.request.path_info)
         return self.request.event.quotas.current.get(
             identity=url.kwargs['quota']
         )
 
-    def get_context_data(self, *args, **kwargs):
+    def get_context_data(self, *args, **kwargs) -> dict:
         context = super().get_context_data(*args, **kwargs)
         context['dependent'] = list(self.get_object().items.current.all())
         return context
@@ -501,7 +506,7 @@ class QuotaDelete(EventPermissionRequiredMixin, DeleteView):
         self.object.delete()
         return HttpResponseRedirect(success_url)
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.items.quotas', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -512,7 +517,7 @@ class ItemDetailMixin(SingleObjectMixin):
     model = Item
     context_object_name = 'item'
 
-    def get_object(self, queryset=None):
+    def get_object(self, queryset=None) -> Item:
         if not hasattr(self, 'object') or not self.object:
             url = resolve(self.request.path_info)
             self.item = self.request.event.items.current.get(
@@ -551,7 +556,7 @@ class ItemUpdateGeneral(ItemDetailMixin, EventPermissionRequiredMixin, UpdateVie
     template_name = 'tixlcontrol/item/index.html'
     permission = 'can_change_items'
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.item', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,
@@ -578,7 +583,7 @@ class ItemVariations(ItemDetailMixin, EventPermissionRequiredMixin, TemplateView
         super().__init__(*args, **kwargs)
         self.item = None
 
-    def get_form(self, variation, data=None):
+    def get_form(self, variation, data=None) -> ItemVariationForm:
         """
         Return the dict for one given variation. Variations are expected to be
         dictionaries in the format of Item.get_all_variations()
@@ -603,7 +608,7 @@ class ItemVariations(ItemDetailMixin, EventPermissionRequiredMixin, TemplateView
         form.values = values
         return form
 
-    def get_forms(self):
+    def get_forms(self) -> tuple:
         """
         Returns one form per possible item variation. The forms are returned
         twice: The first entry in the returned tuple contains a 1-, 2- or
@@ -705,7 +710,7 @@ class ItemVariations(ItemDetailMixin, EventPermissionRequiredMixin, TemplateView
         # TODO: Redirect to success message
         return self.render_to_response(context)
 
-    def get_template_names(self):
+    def get_template_names(self) -> "List[str]":
         if self.dimension == 0:
             return ['tixlcontrol/item/variations_0d.html']
         elif self.dimension == 1:
@@ -713,7 +718,7 @@ class ItemVariations(ItemDetailMixin, EventPermissionRequiredMixin, TemplateView
         elif self.dimension >= 2:
             return ['tixlcontrol/item/variations_nd.html']
 
-    def get_context_data(self, **kwargs):
+    def get_context_data(self, **kwargs) -> dict:
         context = super().get_context_data(**kwargs)
         context['forms'] = self.forms
         context['properties'] = self.properties
@@ -768,12 +773,12 @@ class ItemRestrictions(ItemDetailMixin, EventPermissionRequiredMixin, TemplateVi
             context = self.get_context_data(object=self.object)
             return self.render_to_response(context)
 
-    def get_context_data(self, *args, **kwargs):
+    def get_context_data(self, *args, **kwargs) -> dict:
         context = super().get_context_data(*args, **kwargs)
         context['formsets'] = self.formsets
         return context
 
-    def get_success_url(self):
+    def get_success_url(self) -> str:
         return reverse('control:event.item.restrictions', kwargs={
             'organizer': self.request.event.organizer.slug,
             'event': self.request.event.slug,