diff --git a/ereuse_devicehub/resources/device/models.py b/ereuse_devicehub/resources/device/models.py
index 062acfd2..4b3ac8c3 100644
--- a/ereuse_devicehub/resources/device/models.py
+++ b/ereuse_devicehub/resources/device/models.py
@@ -489,7 +489,10 @@ class DataStorage(JoinedComponentTableMixin, Component):
 
     @property
     def privacy(self):
-        """Returns the privacy compliance state of the data storage."""
+        """Returns the privacy compliance state of the data storage.
+
+        This is, the last erasure performed to the data storage.
+        """
         from ereuse_devicehub.resources.event.models import EraseBasic
         try:
             ev = self.last_event_of(EraseBasic)
diff --git a/ereuse_devicehub/resources/device/views.py b/ereuse_devicehub/resources/device/views.py
index 0eead26c..1ec1736a 100644
--- a/ereuse_devicehub/resources/device/views.py
+++ b/ereuse_devicehub/resources/device/views.py
@@ -62,6 +62,7 @@ class Filters(query.Query):
 class Sorting(query.Sort):
     id = query.SortField(Device.id)
     created = query.SortField(Device.created)
+    updated = query.SortField(Device.updated)
 
 
 class DeviceView(View):
diff --git a/ereuse_devicehub/resources/event/schemas.py b/ereuse_devicehub/resources/event/schemas.py
index b32f2dec..3f100bab 100644
--- a/ereuse_devicehub/resources/event/schemas.py
+++ b/ereuse_devicehub/resources/event/schemas.py
@@ -75,6 +75,7 @@ class Deallocate(EventWithMultipleDevices):
 class EraseBasic(EventWithOneDevice):
     steps = NestedOn('Step', many=True)
     standards = f.List(EnumField(enums.ErasureStandards), dump_only=True)
+    certificate = URL(dump_only=True)
 
 
 class EraseSectors(EraseBasic):
diff --git a/ereuse_devicehub/resources/lot/models.py b/ereuse_devicehub/resources/lot/models.py
index a8615358..baebd05b 100644
--- a/ereuse_devicehub/resources/lot/models.py
+++ b/ereuse_devicehub/resources/lot/models.py
@@ -75,6 +75,10 @@ class Lot(Thing):
         super().__init__(id=uuid.uuid4(), name=name, closed=closed, description=description)
         Path(self)  # Lots have always one edge per default.
 
+    @property
+    def type(self) -> str:
+        return self.__class__.__name__
+
     @property
     def url(self) -> urlutils.URL:
         """The URL where to GET this event."""
diff --git a/ereuse_devicehub/resources/tag/model.py b/ereuse_devicehub/resources/tag/model.py
index a4692f6e..85b7d68e 100644
--- a/ereuse_devicehub/resources/tag/model.py
+++ b/ereuse_devicehub/resources/tag/model.py
@@ -89,6 +89,10 @@ class Tag(Thing):
         UniqueConstraint(secondary, org_id, name='one secondary tag per organization')
     )
 
+    @property
+    def type(self) -> str:
+        return self.__class__.__name__
+
     def __repr__(self) -> str:
         return '<Tag {0.id} org:{0.org_id} device:{0.device_id}>'.format(self)