diff --git a/ereuse_devicehub/client.py b/ereuse_devicehub/client.py
index b5304ed9..b7b38da1 100644
--- a/ereuse_devicehub/client.py
+++ b/ereuse_devicehub/client.py
@@ -106,7 +106,7 @@ class Client(TealClient):
     def login(self, email: str, password: str):
         assert isinstance(email, str)
         assert isinstance(password, str)
-        return self.post({'email': email, 'password': password}, '/users/login', status=200)
+        return self.post({'email': email, 'password': password}, '/users/login/', status=200)
 
     def get_many(self,
                  res: ResourceLike,
diff --git a/ereuse_devicehub/resources/documents/templates/documents/erasure.html b/ereuse_devicehub/resources/documents/templates/documents/erasure.html
index 908bdbe8..29e1d138 100644
--- a/ereuse_devicehub/resources/documents/templates/documents/erasure.html
+++ b/ereuse_devicehub/resources/documents/templates/documents/erasure.html
@@ -16,9 +16,11 @@
       <tbody>
       {% for erasure in erasures %}
         <tr>
-          <td>
-            {{ erasure.parent.serial_number.upper() }}
-          </td>
+          {% if erasure.parent.serial_number %}
+            <td>
+              {{ erasure.parent.serial_number.upper() }}
+            </td>
+          {% endif %}
           <td>
             {{ erasure.parent.tags }}
           </td>
diff --git a/ereuse_devicehub/resources/event/views.py b/ereuse_devicehub/resources/event/views.py
index 30f75a0a..570a4062 100644
--- a/ereuse_devicehub/resources/event/views.py
+++ b/ereuse_devicehub/resources/event/views.py
@@ -4,6 +4,7 @@ from uuid import UUID
 
 from flask import current_app as app, request
 from sqlalchemy.util import OrderedSet
+from teal.marshmallow import ValidationError
 from teal.resource import View
 
 from ereuse_devicehub.db import db
@@ -16,6 +17,8 @@ class EventView(View):
     def post(self):
         """Posts an event."""
         json = request.get_json(validate=False)
+        if 'type' not in json:
+            raise ValidationError('Resource needs a type.')
         e = app.resources[json['type']].schema.load(json)
         Model = db.Model._decl_class_registry.data[json['type']]()
         event = Model(**e)
diff --git a/ereuse_devicehub/resources/tag/model.py b/ereuse_devicehub/resources/tag/model.py
index 85b7d68e..5238d846 100644
--- a/ereuse_devicehub/resources/tag/model.py
+++ b/ereuse_devicehub/resources/tag/model.py
@@ -1,11 +1,13 @@
 from contextlib import suppress
 from typing import Set
 
+from boltons import urlutils
 from sqlalchemy import BigInteger, Column, ForeignKey, Unicode, UniqueConstraint
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import backref, relationship, validates
 from teal.db import DB_CASCADE_SET_NULL, Query, URL, check_lower
 from teal.marshmallow import ValidationError
+from teal.resource import url_for_resource
 
 from ereuse_devicehub.resources.agent.models import Organization
 from ereuse_devicehub.resources.device.models import Device
@@ -93,6 +95,21 @@ class Tag(Thing):
     def type(self) -> str:
         return self.__class__.__name__
 
+    @property
+    def url(self) -> urlutils.URL:
+        """The URL where to GET this device."""
+        # todo this url only works for printable internal tags
+        return urlutils.URL(url_for_resource(Tag, item_id=self.id))
+
+    @property
+    def printable(self) -> bool:
+        """Can the tag be printed by the user?
+
+        Only tags that are from the default organization can be
+        printed by the user.
+        """
+        return Organization.get_default_org_id == self.org_id
+
     def __repr__(self) -> str:
         return '<Tag {0.id} org:{0.org_id} device:{0.device_id}>'.format(self)
 
diff --git a/ereuse_devicehub/resources/tag/model.pyi b/ereuse_devicehub/resources/tag/model.pyi
index 96082341..8e365551 100644
--- a/ereuse_devicehub/resources/tag/model.pyi
+++ b/ereuse_devicehub/resources/tag/model.pyi
@@ -1,5 +1,6 @@
 from uuid import UUID
 
+from boltons import urlutils
 from boltons.urlutils import URL
 from sqlalchemy import Column
 from sqlalchemy.orm import relationship
@@ -39,3 +40,11 @@ class Tag(Thing):
 
     def like_etag(self) -> bool:
         pass
+
+    @property
+    def printable(self) -> bool:
+        pass
+
+    @property
+    def url(self) -> urlutils.URL:
+        pass
diff --git a/ereuse_devicehub/resources/tag/schema.py b/ereuse_devicehub/resources/tag/schema.py
index f41532df..22a492d5 100644
--- a/ereuse_devicehub/resources/tag/schema.py
+++ b/ereuse_devicehub/resources/tag/schema.py
@@ -1,4 +1,5 @@
 from sqlalchemy.util import OrderedSet
+from marshmallow.fields import Boolean
 from teal.marshmallow import SanitizedStr, URL
 
 from ereuse_devicehub.marshmallow import NestedOn
@@ -23,3 +24,5 @@ class Tag(Thing):
     device = NestedOn(Device, dump_only=True)
     org = NestedOn(Organization, collection_class=OrderedSet, only_query='id')
     secondary = SanitizedStr(lower=True, description=m.Tag.secondary.comment)
+    printable = Boolean(dump_only=True, decsription=m.Tag.printable.__doc__)
+    url = URL(dump_only=True, description=m.Tag.url.__doc__)
diff --git a/ereuse_devicehub/resources/user/__init__.py b/ereuse_devicehub/resources/user/__init__.py
index 77ad9677..f3c4b61f 100644
--- a/ereuse_devicehub/resources/user/__init__.py
+++ b/ereuse_devicehub/resources/user/__init__.py
@@ -20,7 +20,7 @@ class UserDef(Resource):
         cli_commands = ((self.create_user, 'create-user'),)
         super().__init__(app, import_name, static_folder, static_url_path, template_folder,
                          url_prefix, subdomain, url_defaults, root_path, cli_commands)
-        self.add_url_rule('/login', view_func=login, methods={'POST'})
+        self.add_url_rule('/login/', view_func=login, methods={'POST'})
 
     @argument('email')
     @option('-a', '--agent', help='The name of an agent to create with the user.')
diff --git a/setup.py b/setup.py
index 8f6c261b..70e82c27 100644
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@ test_requires = [
 
 setup(
     name='ereuse-devicehub',
-    version='0.2.0b2',
+    version='0.2.0b3',
     url='https://github.com/ereuse/devicehub-teal',
     project_urls=OrderedDict((
         ('Documentation', 'http://devicheub.ereuse.org'),
diff --git a/tests/test_basic.py b/tests/test_basic.py
index debb4c64..7fc1a29c 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -22,7 +22,7 @@ def test_api_docs(client: Client):
         '/devices/',
         '/tags/',
         '/snapshots/',
-        '/users/login',
+        '/users/login/',
         '/events/',
         '/lots/',
         '/manufacturers/',
diff --git a/tests/test_user.py b/tests/test_user.py
index 7a8410b5..aab20746 100644
--- a/tests/test_user.py
+++ b/tests/test_user.py
@@ -74,7 +74,7 @@ def test_login_success(client: Client, app: Devicehub):
     with app.app_context():
         create_user()
     user, _ = client.post({'email': 'foo@foo.com', 'password': 'foo'},
-                          uri='/users/login',
+                          uri='/users/login/',
                           status=200)
     assert user['email'] == 'foo@foo.com'
     assert UUID(b64decode(user['token'].encode()).decode()[:-1])
@@ -90,12 +90,12 @@ def test_login_failure(client: Client, app: Devicehub):
     with app.app_context():
         create_user()
     client.post({'email': 'foo@foo.com', 'password': 'wrong pass'},
-                uri='/users/login',
+                uri='/users/login/',
                 status=WrongCredentials)
     # Wrong URI
     client.post({}, uri='/wrong-uri', status=NotFound)
     # Malformed data
-    client.post({}, uri='/users/login', status=ValidationError)
+    client.post({}, uri='/users/login/', status=ValidationError)
     client.post({'email': 'this is not an email', 'password': 'nope'},
-                uri='/users/login',
+                uri='/users/login/',
                 status=ValidationError)