diff --git a/addons/mail/data/mail_data.xml b/addons/mail/data/mail_data.xml
index 8b4c4ddcc65..8afde76abfd 100644
--- a/addons/mail/data/mail_data.xml
+++ b/addons/mail/data/mail_data.xml
@@ -68,5 +68,11 @@
             <field name="name">Discussions</field>
             <field name="sequence" eval="0"/>
         </record>
+        <record id="mt_note" model="mail.message.subtype">
+            <field name="name">Note</field>
+            <field name="default" eval="False"/>
+            <field name="internal" eval="True"/>
+            <field name="sequence" eval="100"/>
+        </record>
     </data>
 </openerp>
diff --git a/addons/mail/models/mail_message.py b/addons/mail/models/mail_message.py
index 7e191f9517d..44c0e254776 100644
--- a/addons/mail/models/mail_message.py
+++ b/addons/mail/models/mail_message.py
@@ -541,7 +541,7 @@ class Message(models.Model):
                 count=count, access_rights_uid=access_rights_uid)
         # Non-employee see only messages with a subtype (aka, no internal logs)
         if not self.env['res.users'].has_group('base.group_user'):
-            args = ['&', ('subtype_id', '!=', False)] + list(args)
+            args = ['&', '&', ('subtype_id', '!=', False), ('subtype_id.internal', '=', False)] + list(args)
         # Perform a super with count as False, to have the ids, not a counter
         ids = super(Message, self)._search(
             args, offset=offset, limit=limit, order=order,
@@ -620,7 +620,11 @@ class Message(models.Model):
             return
         # Non employees see only messages with a subtype (aka, not internal logs)
         if not self.env['res.users'].has_group('base.group_user'):
-            self._cr.execute('SELECT DISTINCT id FROM "%s" WHERE message_type = %%s AND subtype_id IS NULL AND id = ANY (%%s)' % (self._table), ('comment', self.ids,))
+            self._cr.execute('''SELECT DISTINCT message.id, message.subtype_id, subtype.internal
+                                FROM "%s" AS message
+                                LEFT JOIN "mail_message_subtype" as subtype
+                                ON message.subtype_id = subtype.id
+                                WHERE message.message_type = %%s AND (message.subtype_id IS NULL OR subtype.internal IS TRUE) AND message.id = ANY (%%s)''' % (self._table), ('comment', self.ids,))
             if self._cr.fetchall():
                 raise AccessError(
                     _('The requested operation cannot be completed due to security restrictions. Please contact your system administrator.\n\n(Document type: %s, Operation: %s)') %
@@ -783,10 +787,16 @@ class Message(models.Model):
         self.ensure_one()  # tde: not sure, just for testinh, will see
         partners_to_notify = self.env['res.partner']
 
-        # all followers of the mail.message document have to be added as partners and notified if a subtype is defined (otherwise: log message)
+        # all followers of the mail.message document have to be added as partners and notified
+        # and filter to employees only if the subtype is internal
         if self.subtype_id and self.model and self.res_id:
-            followers = self.env['mail.followers'].sudo().search([('res_model', '=', self.model), ('res_id', '=', self.res_id)])
-            partners_to_notify |= followers.filtered(lambda fol: self.subtype_id in fol.subtype_ids).mapped('partner_id')
+            followers = self.env['mail.followers'].sudo().search([
+                ('res_model', '=', self.model),
+                ('res_id', '=', self.res_id)
+            ]).filtered(lambda fol: self.subtype_id in fol.subtype_ids)
+            if self.subtype_id.internal:
+                followers.filtered(lambda fol: fol.partner_id.user_ids and fol.partner_id.user_ids[0].has_group('base.group_user'))
+            partners_to_notify |= followers.mapped('partner_id')
 
         # remove me from notified partners, unless the message is written on my own wall
         if self.subtype_id and self.author_id and self.model == "res.partner" and self.res_id == self.author_id.id:
diff --git a/addons/mail/models/mail_message_subtype.py b/addons/mail/models/mail_message_subtype.py
index 26faa0a3e12..83d3f082159 100644
--- a/addons/mail/models/mail_message_subtype.py
+++ b/addons/mail/models/mail_message_subtype.py
@@ -22,9 +22,14 @@ class MailMessageSubtype(models.Model):
         'Description', translate=True,
         help='Description that will be added in the message posted for this '
              'subtype. If void, the name will be added instead.')
+    internal = fields.Boolean(
+        'Internal Only',
+        help='Messages with internal subtypes will be visible only by employees, aka members of base_user group')
     parent_id = fields.Many2one(
         'mail.message.subtype', string='Parent', ondelete='set null',
-        help='Parent subtype, used for automatic subscription.')
+        help='Parent subtype, used for automatic subscription. This field is not'
+             'correctly named. For example on a project, project subtypes have'
+             'parent_id to task-related subtypes.')
     relation_field = fields.Char(
         'Relation field',
         help='Field used to link the related model to the subtype model when '
diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 5b9755cafc8..a91b7c18768 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -336,8 +336,17 @@ class MailThread(models.AbstractModel):
         if view_type == 'form':
             doc = etree.XML(res['arch'])
             for node in doc.xpath("//field[@name='message_ids']"):
+                # the 'Log a note' button is employee only
                 options = json.loads(node.get('options', '{}'))
-                options['display_log_button'] = self.env.user.sudo().has_group('base.group_user')
+                is_employee = self.env.user.has_group('base.group_user')
+                options['display_log_button'] = is_employee
+                if is_employee:
+                    Subtype = self.env['mail.message.subtype'].sudo()
+                    # fetch internal subtypes
+                    internal_subtypes = Subtype.search_read([
+                        ('res_model', 'in', [False, self._name]),
+                        ('internal', '=', True)], ['name', 'description', 'sequence'])
+                    options['internal_subtypes'] = internal_subtypes
                 node.set('options', json.dumps(options))
             res['arch'] = etree.tostring(doc)
         return res
@@ -1552,8 +1561,9 @@ class MailThread(models.AbstractModel):
             attachments, kwargs.pop('attachment_ids', []), model, self.ids and self.ids[0] or None)
 
         # 4: mail.message.subtype
-        subtype_id = False
-        if subtype:
+        subtype_id = kwargs.get('subtype_id', False)
+        if not subtype_id:
+            subtype = subtype or 'mt_note'
             if '.' not in subtype:
                 subtype = 'mail.%s' % subtype
             subtype_id = self.env['ir.model.data'].xmlid_to_res_id(subtype)
@@ -1607,8 +1617,10 @@ class MailThread(models.AbstractModel):
 
         # Post-process: subscribe author, update message_last_post
         if model and model != 'mail.thread' and self.ids and subtype_id:
-            # done with SUPERUSER_ID, because on some models users can post only with read access, not necessarily write access
-            self.sudo().write({'message_last_post': fields.datetime.now()})
+            subtype_rec = self.env['mail.message.subtype'].sudo().browse(subtype_id)
+            if not subtype_rec.internal:
+                # done with SUPERUSER_ID, because on some models users can post only with read access, not necessarily write access
+                self.sudo().write({'message_last_post': fields.Datetime.now()})
         if new_message.author_id and model and self.ids and message_type != 'notification' and not self._context.get('mail_create_nosubscribe'):
             self.message_subscribe([new_message.author_id.id])
         return new_message
diff --git a/addons/mail/security/ir.model.access.csv b/addons/mail/security/ir.model.access.csv
index c8f90dcaeac..c66045d6fe8 100644
--- a/addons/mail/security/ir.model.access.csv
+++ b/addons/mail/security/ir.model.access.csv
@@ -20,7 +20,7 @@ access_mail_alias_all,mail.alias.all,model_mail_alias,,1,0,0,0
 access_mail_alias_user,mail.alias.user,model_mail_alias,base.group_user,1,1,1,0
 access_mail_alias_system,mail.alias.system,model_mail_alias,base.group_system,1,1,1,1
 access_mail_message_subtype_all,mail.message.subtype.all,model_mail_message_subtype,,1,0,0,0
-access_mail_message_subtype_system,mail.message.subtype.system,model_mail_message_subtype,base.group_system,1,1,1,1
+access_mail_message_subtype_user,mail.message.subtype.user,model_mail_message_subtype,,1,1,1,1
 access_mail_tracking_value_all,mail.tracking.value.all,model_mail_tracking_value,,1,0,0,0
 access_mail_tracking_value_portal,mail.tracking.value.portal,model_mail_tracking_value,base.group_portal,1,1,1,1
 access_mail_tracking_value_user,mail.tracking.value.user,model_mail_tracking_value,base.group_user,1,1,1,1
diff --git a/addons/mail/security/mail_security.xml b/addons/mail/security/mail_security.xml
index 5384e2aba95..2f07c659c95 100644
--- a/addons/mail/security/mail_security.xml
+++ b/addons/mail/security/mail_security.xml
@@ -38,6 +38,13 @@
             <field name="perm_unlink" eval="False"/>
         </record>
 
+        <record id="mail_message_subtype_rule_public" model="ir.rule">
+            <field name="name">mail.message.subtype: portal/public: read public subtypes</field>
+            <field name="model_id" ref="model_mail_message_subtype"/>
+            <field name="domain_force">[('internal', '=', False)]</field>
+            <field name="groups" eval="[(4, ref('base.group_portal')), (4, ref('base.group_public'))]"/>
+        </record>
+
         <!--
         This rule can not be uncommented, because we have a more wide method in mail.message. When we implement a many2one_variable field, we will be able to uncomment this.
         <record id="mail_message_read_partner_or_author" model="ir.rule">
diff --git a/addons/mail/static/src/js/mail.js b/addons/mail/static/src/js/mail.js
index fb78f11b7cc..e246c504119 100644
--- a/addons/mail/static/src/js/mail.js
+++ b/addons/mail/static/src/js/mail.js
@@ -50,6 +50,7 @@ var TimelineRecordThread = form_common.AbstractField.extend ({
             'readonly': this.node.attrs.readonly || false,
             'compose_placeholder' : this.node.attrs.placeholder || false,
             'display_log_button' : this.options.display_log_button || true,
+            'internal_subtypes' : this.options.internal_subtypes || [],
             'show_compose_message': true,
             'show_link': this.parent.is_action_enabled('edit') || true,
         }, this.node.params);
@@ -1218,10 +1219,16 @@ var ComposeMessage = Attachment.extend ({
             'content_subtype': 'plaintext',
         };
 
-        if(log){
-            values.subtype = false;
-        }else{
-            values.subtype = 'mail.mt_comment';
+        if (log) {
+            var subtype_id = parseInt(this.$('select').first().val());
+            if (_.indexOf(_.pluck(self.options.internal_subtypes, 'id'), subtype_id) == -1) {
+                values['subtype'] = 'mail.mt_note'
+            }
+            else {
+                values['subtype_id'] = subtype_id;
+            }
+        } else {
+            values['subtype'] = 'mail.mt_comment';
         }
 
         this.parent_thread.ds_thread._model.call('message_post', [this.context.default_res_id], values).done(function (message_id) {
diff --git a/addons/mail/static/src/xml/mail.xml b/addons/mail/static/src/xml/mail.xml
index 539c587c80e..d5a188f5e40 100644
--- a/addons/mail/static/src/xml/mail.xml
+++ b/addons/mail/static/src/xml/mail.xml
@@ -37,10 +37,18 @@
         <div class="o_timeline_msg o_timeline_msg_composer">
             <div class="o_timeline_msg_center">
                 <div class="o_timeline_msg_content">
-                    <button class="oe_full" title="Open the full mail composer">
+                    <button t-if="! widget.is_log" class="oe_full" title="Open the full mail composer">
                         <i class='fa fa-pencil-square-o'/>
                     </button>
                     <t t-call="ThreadListRecipients"/>
+                    <t t-if="widget.is_log and widget.options.internal_subtypes.length > 1">
+                        <label>Activity</label>
+                        <select class="">
+                            <t t-foreach="widget.options.internal_subtypes" t-as="subtype">
+                                <option t-att-value="subtype['id']"><t t-raw="subtype['name']"/></option>
+                            </t>
+                        </select>
+                    </t>
                     <textarea class="field_text"></textarea>
                 </div>
                 <div class="o_timeline_msg_footer">
diff --git a/addons/mail/tests/test_mail_followers.py b/addons/mail/tests/test_mail_followers.py
index 5cbb5961f03..0c36da2c4f9 100644
--- a/addons/mail/tests/test_mail_followers.py
+++ b/addons/mail/tests/test_mail_followers.py
@@ -89,7 +89,7 @@ class TestMailFollowers(TestMail):
     def test_subscription_data(self):
         self.group_pigs.message_subscribe_users(user_ids=[self.user_employee.id])
         subtype_data = self.group_pigs.sudo(self.user_employee)._get_subscription_data()[self.group_pigs.id]['message_subtype_data']
-        self.assertEqual(set(subtype_data.keys()), set(['Discussions', 'mt_mg_def', 'mt_al_def', 'mt_mg_nodef', 'mt_al_nodef']), 'mail.group available subtypes incorrect')
+        self.assertEqual(set(subtype_data.keys()), set(['Discussions', 'Note', 'mt_mg_def', 'mt_al_def', 'mt_mg_nodef', 'mt_al_nodef']), 'mail.group available subtypes incorrect')
         self.assertTrue(subtype_data['Discussions']['followed'])
         self.assertFalse(subtype_data['mt_mg_nodef']['followed'])
         self.assertFalse(subtype_data['mt_al_nodef']['followed'])
diff --git a/addons/mail/tests/test_message_track.py b/addons/mail/tests/test_message_track.py
index 195d1d3c770..9f292fe00cf 100644
--- a/addons/mail/tests/test_message_track.py
+++ b/addons/mail/tests/test_message_track.py
@@ -12,6 +12,7 @@ class TestTracking(TestMail):
             return body.replace(' ', '').replace('\n', '')
         Subtype = self.env['mail.message.subtype']
         Data = self.env['ir.model.data']
+        note_subtype = self.env.ref('mail.mt_note')
 
         group_system = self.env.ref('base.group_system')
         group_user = self.env.ref('base.group_user')
@@ -97,7 +98,7 @@ class TestTracking(TestMail):
         self.group_pigs.sudo(self.user_employee).write({'name': 'my_name'})
         self.assertEqual(len(self.group_pigs.message_ids), 1)
         last_msg = self.group_pigs.message_ids[-1]
-        self.assertFalse(last_msg.subtype_id)
+        self.assertEqual(last_msg.subtype_id, note_subtype)
         self.assertEqual(len(last_msg.tracking_value_ids), 1)
         self.assertEqual(last_msg.tracking_value_ids.field, 'name')
         self.assertEqual(last_msg.tracking_value_ids.field_desc, 'Name')
diff --git a/addons/mail/views/mail_message_subtype_views.xml b/addons/mail/views/mail_message_subtype_views.xml
index 8b7856bea22..6ec50c7ef06 100644
--- a/addons/mail/views/mail_message_subtype_views.xml
+++ b/addons/mail/views/mail_message_subtype_views.xml
@@ -29,6 +29,7 @@
                                 <field name="res_model"/>
                                 <field name="description"/>
                                 <field name="default"/>
+                                <field name="internal"/>
                                 <field name="hidden"/>
                             </group>
                             <group string='Auto subscription'>
diff --git a/addons/portal/tests/test_portal.py b/addons/portal/tests/test_portal.py
index 00d260f2862..65703cd973d 100644
--- a/addons/portal/tests/test_portal.py
+++ b/addons/portal/tests/test_portal.py
@@ -10,7 +10,7 @@ class test_portal(TestMail):
         port_msg = self.group_portal.message_post(body='Message')
 
         # Do: Chell comments Pigs, ok because can write on it (public group)
-        self.group_portal.sudo(self.user_portal).message_post(body='I love Pigs')
+        self.group_portal.sudo(self.user_portal).message_post(body='I love Pigs', message_type='comment', subtype='mail.mt_comment')
         # Do: Chell creates a mail.compose.message record on Pigs, because he uses the wizard
         compose = self.env['mail.compose.message'].with_context({
             'default_composition_mode': 'comment',