diff --git a/addons/event/views/event_views.xml b/addons/event/views/event_views.xml
index ffc04deca47..1977634b90a 100644
--- a/addons/event/views/event_views.xml
+++ b/addons/event/views/event_views.xml
@@ -468,7 +468,7 @@
                                 <field name="email"/>
                             </group>
                             <group string="Event Information" name="event">
-                                <field name="event_id" attrs="{'readonly': [('state', '!=', 'draft')]}"/>
+                                <field name="event_id" attrs="{'readonly': [('state', '!=', 'draft')]}" options="{'no_open': True, 'no_create': True}"/>
                                 <field name="date_open" groups="base.group_no_one"/>
                                 <field name="date_closed" groups="base.group_no_one"/>
                             </group>
diff --git a/addons/event_sale/models/event.py b/addons/event_sale/models/event.py
index 1f9a7ed53b0..0ab88b3be85 100644
--- a/addons/event_sale/models/event.py
+++ b/addons/event_sale/models/event.py
@@ -160,17 +160,43 @@ class EventTicket(models.Model):
     def _onchange_product_id(self):
         self.price = self.product_id.list_price or 0
 
+    def get_ticket_multiline_description_sale(self):
+        """ Compute a multiline description of this ticket, in the context of sales.
+            It will often be used as the default description of a sales order line referencing this ticket.
+
+        1. the first line is the ticket name
+        2. the second line is the event name (if it exists, which should be the case with a normal workflow) or the product name (if it exists)
+
+        We decided to ignore entirely the product name and the product description_sale because they are considered to be replaced by the ticket name and event name.
+            -> the workflow of creating a new event also does not lead to filling them correctly, as the product is created through the event interface
+        """
+
+        name = self.display_name
+
+        if self.event_id:
+            name += '\n' + self.event_id.display_name
+        elif self.product_id:
+            name += '\n' + self.product_id.display_name
+
+        return name
+
 
 class EventRegistration(models.Model):
     _inherit = 'event.registration'
 
-    event_ticket_id = fields.Many2one('event.event.ticket', string='Event Ticket')
+    event_ticket_id = fields.Many2one('event.event.ticket', string='Event Ticket', readonly=True, states={'draft': [('readonly', False)]})
     # in addition to origin generic fields, add real relational fields to correctly
     # handle attendees linked to sales orders and their lines
     # TDE FIXME: maybe add an onchange on sale_order_id + origin
     sale_order_id = fields.Many2one('sale.order', string='Source Sales Order', ondelete='cascade')
     sale_order_line_id = fields.Many2one('sale.order.line', string='Sales Order Line', ondelete='cascade')
 
+    @api.onchange('event_id')
+    def _onchange_event_id(self):
+        # We reset the ticket when keeping it would lead to an inconstitent state.
+        if self.event_ticket_id and (not self.event_id or self.event_id != self.event_ticket_id.event_id):
+            self.event_ticket_id = None
+
     @api.multi
     @api.constrains('event_ticket_id', 'state')
     def _check_ticket_seats_limit(self):
diff --git a/addons/event_sale/models/sale_order.py b/addons/event_sale/models/sale_order.py
index a4601ac5f76..c41a6218f10 100644
--- a/addons/event_sale/models/sale_order.py
+++ b/addons/event_sale/models/sale_order.py
@@ -27,14 +27,6 @@ class SaleOrderLine(models.Model):
         "an event ticket and it will automatically create a registration for this event ticket.")
     event_ok = fields.Boolean(related='product_id.event_ok', readonly=True)
 
-    @api.multi
-    def _prepare_invoice_line(self, qty):
-        self.ensure_one()
-        res = super(SaleOrderLine, self)._prepare_invoice_line(qty)
-        if self.event_id:
-            res['name'] = '%s: %s' % (res.get('name', ''), self.event_id.name)
-        return res
-
     @api.multi
     def _update_registrations(self, confirm=True, cancel_to_draft=False, registration_data=None):
         """ Create or update registrations linked to a sales order line. A sale
@@ -60,9 +52,40 @@ class SaleOrderLine(models.Model):
                     Registration._prepare_attendee_values(registration))
         return True
 
+    @api.onchange('product_id')
+    def _onchange_product_id(self):
+        # We reset the event when keeping it would lead to an inconstitent state.
+        # We need to do it this way because the only relation between the product and the event is through the corresponding tickets.
+        if self.event_id and (not self.product_id or self.product_id.id not in self.event_id.mapped('event_ticket_ids.product_id.id')):
+            self.event_id = None
+
+    @api.onchange('event_id')
+    def _onchange_event_id(self):
+        # We reset the ticket when keeping it would lead to an inconstitent state.
+        if self.event_ticket_id and (not self.event_id or self.event_id != self.event_ticket_id.event_id):
+            self.event_ticket_id = None
+
     @api.onchange('event_ticket_id')
     def _onchange_event_ticket_id(self):
         company = self.event_id.company_id or self.env.user.company_id
         currency = company.currency_id
         self.price_unit = currency._convert(
             self.event_ticket_id.price, self.order_id.currency_id, self.order_id.company_id, self.order_id.date_order or fields.Date.today())
+
+        # we call this to force update the default name
+        self.product_id_change()
+
+    def get_sale_order_line_multiline_description_sale(self, product):
+        """ We override this method because we decided that:
+                The default description of a sales order line containing a ticket must be different than the default description when no ticket is present.
+                So in that case we use the description computed from the ticket, instead of the description computed from the product.
+                We need this override to be defined here in sales order line (and not in product) because here is the only place where the event_ticket_id is referenced.
+        """
+        if self.event_ticket_id:
+            ticket = self.event_ticket_id.with_context(
+                lang=self.order_id.partner_id.lang,
+            )
+
+            return ticket.get_ticket_multiline_description_sale()
+        else:
+            return super(SaleOrderLine, self).get_sale_order_line_multiline_description_sale(product)
diff --git a/addons/event_sale/tests/test_event_sale.py b/addons/event_sale/tests/test_event_sale.py
index d73a1cfcb7e..8f17f322780 100644
--- a/addons/event_sale/tests/test_event_sale.py
+++ b/addons/event_sale/tests/test_event_sale.py
@@ -25,6 +25,12 @@ class EventSaleTest(common.TransactionCase):
             'date_begin': '2012-01-01 18:05:15'
         })
 
+        ticket = self.env['event.event.ticket'].create({
+            'name': 'test_ticket',
+            'product_id': product.id,
+            'event_id': event.id,
+        })
+
         # I create a sales order
         self.sale_order = self.env['sale.order'].create({
             'partner_id': self.env.ref('base.res_partner_2').id,
@@ -40,7 +46,8 @@ class EventSaleTest(common.TransactionCase):
             'product_uom_qty': 8.0,
             'order_id': self.sale_order.id,
             'name': 'sales order line',
-            'event_id': event.id
+            'event_id': event.id,
+            'event_ticket_id': ticket.id,
         })
 
         # In the event registration I add some attendee detail lines. i choose event product
diff --git a/addons/event_sale/views/event_views.xml b/addons/event_sale/views/event_views.xml
index e8498e562e1..778bd166cb3 100644
--- a/addons/event_sale/views/event_views.xml
+++ b/addons/event_sale/views/event_views.xml
@@ -29,7 +29,15 @@
             <field name="inherit_id" ref="event.view_event_registration_form" />
             <field name="arch" type="xml">
                 <field name="event_id" position="after">
-                    <field name="event_ticket_id" domain="[('event_id', '=', event_id)]"/>
+                    <field
+                        name="event_ticket_id"
+                        domain="[
+                            ('event_id', '=', event_id),
+                            '|', ('seats_availability', '=', 'unlimited'), ('seats_available', '>', 0)
+                        ]"
+                        attrs="{'invisible': [('event_id', '=', False)]}"
+                        options="{'no_open': True, 'no_create': True}"
+                    />
                 </field>
                 <group name="event" position="after">
                     <group string="Origin">
diff --git a/addons/event_sale/views/sale_order_views.xml b/addons/event_sale/views/sale_order_views.xml
index 3d2b8530947..712da75ffd8 100644
--- a/addons/event_sale/views/sale_order_views.xml
+++ b/addons/event_sale/views/sale_order_views.xml
@@ -6,8 +6,28 @@
              <field name="inherit_id" ref="sale.view_order_form" />
              <field name="arch" type="xml">
                 <xpath expr="//field[@name='order_line']//form//field[@name='product_id']" position="after">
-                    <field name="event_id" domain="[('event_ticket_ids.product_id','=', product_id),('date_end','&gt;=',time.strftime('%Y-%m-%d 00:00:00'))]" attrs="{'invisible': [('event_ok', '=', False)],'required': [('event_ok', '!=', False)]}"/>
-                    <field name="event_ticket_id" domain="[('event_id', '=', event_id), ('product_id','=',product_id), '|', ('seats_availability', '=', 'unlimited'), ('seats_available', '>', 0)]" attrs="{'invisible': [('event_ok', '=', False)], 'required': [('event_ok', '!=', False)]}"/>
+                    <field
+                        name="event_id"
+                        domain="[
+                            ('event_ticket_ids.product_id','=', product_id),
+                            ('date_end','&gt;=',time.strftime('%Y-%m-%d 00:00:00'))
+                        ]"
+                        attrs="{'invisible': [('event_ok', '=', False)], 'required': [('event_ok', '!=', False)]}"
+                        options="{'no_open': True, 'no_create': True}"
+                    />
+                    <field
+                        name="event_ticket_id"
+                        domain="[
+                            ('event_id', '=', event_id),
+                            ('product_id','=',product_id),
+                            '|', ('seats_availability', '=', 'unlimited'), ('seats_available', '>', 0)
+                        ]"
+                        attrs="{
+                            'invisible': ['|', ('event_ok', '=', False), ('event_id', '=', False)],
+                            'required': [('event_ok', '!=', False), ('event_id', '!=', False)],
+                        }"
+                        options="{'no_open': True, 'no_create': True}"
+                    />
                     <field name="event_ok" invisible="1"/>
                 </xpath>
                 <xpath expr="//field[@name='order_line']//tree//field[@name='product_id']" position="after">
diff --git a/addons/product/models/product.py b/addons/product/models/product.py
index a42b37cf5e7..ccda4b32511 100644
--- a/addons/product/models/product.py
+++ b/addons/product/models/product.py
@@ -572,6 +572,16 @@ class ProductProduct(models.Model):
         )
         return super(ProductProduct, self).get_empty_list_help(help)
 
+    def get_product_multiline_description_sale(self):
+        """ Compute a multiline description of this product, in the context of sales
+                (do not use for purchases or other display reasons that don't intend to use "description_sale").
+            It will often be used as the default description of a sale order line referencing this product.
+        """
+        name = self.display_name
+        if self.description_sale:
+            name += '\n' + self.description_sale
+        return name
+
 
 class ProductPackaging(models.Model):
     _name = "product.packaging"
diff --git a/addons/sale/models/sale.py b/addons/sale/models/sale.py
index cdae56697db..3a66cc1a1f4 100644
--- a/addons/sale/models/sale.py
+++ b/addons/sale/models/sale.py
@@ -1343,10 +1343,7 @@ class SaleOrderLine(models.Model):
                 self.product_id = False
                 return result
 
-        name = product.name_get()[0][1]
-        if product.description_sale:
-            name += '\n' + product.description_sale
-        vals['name'] = name
+        vals.update(name=self.get_sale_order_line_multiline_description_sale(product))
 
         self._compute_tax_id()
 
@@ -1486,3 +1483,12 @@ class SaleOrderLine(models.Model):
     def _is_delivery(self):
         self.ensure_one()
         return False
+
+    def get_sale_order_line_multiline_description_sale(self, product):
+        """ Compute a default multiline description for this sales order line.
+        This method exists so it can be overridden in other modules to change how the default name is computed.
+        In general only the product is used to compute the name, and this method would not be necessary (we could directly override the method in product).
+        BUT in event_sale we need to know specifically the sales order line as well as the product to generate the name:
+            the product is not sufficient because we also need to know the event_id and the event_ticket_id (both which belong to the sale order line).
+        """
+        return product.get_product_multiline_description_sale()
diff --git a/addons/sale_management/models/sale_order.py b/addons/sale_management/models/sale_order.py
index f2481bc7fc5..b8a8d3ad8e8 100644
--- a/addons/sale_management/models/sale_order.py
+++ b/addons/sale_management/models/sale_order.py
@@ -238,9 +238,7 @@ class SaleOrderOption(models.Model):
             return
         product = self.product_id.with_context(lang=self.order_id.partner_id.lang)
         self.price_unit = product.list_price
-        self.name = product.name
-        if product.description_sale:
-            self.name += '\n' + product.description_sale
+        self.name = product.get_product_multiline_description_sale()
         self.uom_id = self.uom_id or product.uom_id
         pricelist = self.order_id.pricelist_id
         if pricelist and product:
diff --git a/addons/website_event/models/event.py b/addons/website_event/models/event.py
index ae07f798939..e4e10667dfc 100644
--- a/addons/website_event/models/event.py
+++ b/addons/website_event/models/event.py
@@ -4,12 +4,9 @@ import logging
 import pytz
 import werkzeug
 
-from datetime import datetime
-
 from odoo import api, fields, models, _
 from odoo.addons.http_routing.models.ir_http import slug
 from odoo.exceptions import UserError
-from odoo.tools import DEFAULT_SERVER_DATETIME_FORMAT
 
 _logger = logging.getLogger(__name__)
 
@@ -162,8 +159,8 @@ class Event(models.Model):
         return result
 
     def _get_event_resource_urls(self, attendees):
-        url_date_start = datetime.strptime(self.date_begin, DEFAULT_SERVER_DATETIME_FORMAT).strftime('%Y%m%dT%H%M%SZ')
-        url_date_stop = datetime.strptime(self.date_end, DEFAULT_SERVER_DATETIME_FORMAT).strftime('%Y%m%dT%H%M%SZ')
+        url_date_start = self.date_begin.strftime('%Y%m%dT%H%M%SZ')
+        url_date_stop = self.date_end.strftime('%Y%m%dT%H%M%SZ')
         params = {
             'action': 'TEMPLATE',
             'text': self.name,
diff --git a/addons/website_event_sale/models/sale_order.py b/addons/website_event_sale/models/sale_order.py
index 3cf2d253182..097ce0adbaf 100644
--- a/addons/website_event_sale/models/sale_order.py
+++ b/addons/website_event_sale/models/sale_order.py
@@ -42,7 +42,7 @@ class SaleOrder(models.Model):
             values['event_id'] = ticket.event_id.id
             values['event_ticket_id'] = ticket.id
             values['price_unit'] = ticket.price_reduce or ticket.price
-            values['name'] = "%s\n%s" % (ticket.event_id.display_name, ticket.name)
+            values['name'] = ticket.get_ticket_multiline_description_sale()
 
         # avoid writing related values that end up locking the product record
         values.pop('event_ok', None)
@@ -96,3 +96,18 @@ class SaleOrder(models.Model):
             # add in return values the registrations, to display them on website (or not)
             values['attendee_ids'] = self.env['event.registration'].search([('sale_order_line_id', '=', line.id), ('state', '!=', 'cancel')]).ids
         return values
+
+
+class SaleOrderLine(models.Model):
+    _inherit = "sale.order.line"
+
+    @api.multi
+    @api.depends('product_id.display_name', 'event_ticket_id.display_name')
+    def _compute_name_short(self):
+        """ If the sale order line concerns a ticket, we don't want the product name, but the ticket name instead.
+        """
+        super(SaleOrderLine, self)._compute_name_short()
+
+        for record in self:
+            if record.event_ticket_id:
+                record.name_short = record.event_ticket_id.display_name
diff --git a/addons/website_event_sale/views/event_templates.xml b/addons/website_event_sale/views/event_templates.xml
index 4be278f9620..bccf05ad8be 100644
--- a/addons/website_event_sale/views/event_templates.xml
+++ b/addons/website_event_sale/views/event_templates.xml
@@ -84,15 +84,54 @@
     </xpath>
 </template>
 
-<template id="cart" inherit_id="website_sale.cart_lines" name="Hide product reduction for event tickets">
-    <xpath expr="//td[hasclass('td-product_name')]/div/a" position="attributes">
+<!-- If the sale order line concerns an event, we want the "product" link to point to the event itself and not to the product on the ecommerce -->
+<template id="cart_line_product_link_inherit_website_event_sale" inherit_id="website_sale.cart_line_product_link" name="Event Shopping Cart Line Product Link">
+    <xpath expr="//a" position="attributes">
         <attribute name="t-attf-href"/>
         <attribute name="t-att-href">
             line.event_id and ('/event/%s/register' % slug(line.event_id)) or ('/shop/product/%s' % slug(line.product_id.product_tmpl_id))
         </attribute>
     </xpath>
+</template>
+
+<!-- If the sale order line concerns an event, we want to show an additional line with the event name even on small screens -->
+<template id="cart_lines_inherit_website_event_sale" inherit_id="website_sale.cart_lines" name="Event Shopping Cart Lines">
+    <xpath expr="//t[@t-call='website_sale.cart_line_description_following_lines']/t[@t-set='div_class']" position="after">
+        <t t-if="line.event_id">
+            <t t-set="div_class" t-value="''"/>
+        </t>
+    </xpath>
+</template>
+
+<!-- If the sale order line concerns an event, we want to show an additional line with the event name -->
+<template id="cart_popover_inherit_website_event_sale" inherit_id="website_sale.cart_popover" name="Event Cart Popover">
+    <xpath expr="//t[@t-call='website_sale.cart_line_product_link']" position="after">
+        <t t-if="line.event_id" t-call="website_sale.cart_line_description_following_lines"/>
+    </xpath>
+</template>
+
+<!-- If the sale order line concerns an event, we want to show an additional line with the event name -->
+<template id="cart_summary_inherit_website_event_sale" inherit_id="website_sale.cart_summary" name="Event Cart right column">
+    <xpath expr="//td[hasclass('td-product_name')]/div/strong" position="after">
+        <t t-if="line.event_id" t-call="website_sale.cart_line_description_following_lines"/>
+    </xpath>
+</template>
+
+<template id="cart_lines_inherit_website_event_sale" inherit_id="website_sale.cart_lines" name="Hide product reduction for event tickets">
     <xpath expr="//del" position="attributes">
         <attribute name="t-attf-class" separator=" " add="#{line.event_id and 'd-none' or ''}"/>
     </xpath>
 </template>
+
+<!-- Add the ticket name on the registration complete page. -->
+<template id="registration_complete_inherit_website_event_sale" inherit_id="website_event.registration_complete" name="Sale Registration Completed">
+    <xpath expr="//thead/tr/th[1]" position="after">
+        <th>Ticket</th>
+    </xpath>
+    <xpath expr="//tbody/t/tr/td[1]" position="after">
+        <td><i class="fa fa-ticket"></i> <t t-if='attendee.event_ticket_id'><t t-esc="attendee.event_ticket_id.name"/></t><t t-if='not attendee.event_ticket_id'>N/A</t></td>
+    </xpath>
+</template>
+
 </odoo>
+
diff --git a/addons/website_sale/models/sale_order.py b/addons/website_sale/models/sale_order.py
index a48436c1433..8d8fd395045 100644
--- a/addons/website_sale/models/sale_order.py
+++ b/addons/website_sale/models/sale_order.py
@@ -239,3 +239,21 @@ class SaleOrder(models.Model):
         self.modified(['create_date'])
         if self.env.recompute and self.env.context.get('recompute', True):
             self.recompute()
+
+
+class SaleOrderLine(models.Model):
+    _inherit = "sale.order.line"
+
+    name_short = fields.Char(compute="_compute_name_short")
+
+    @api.multi
+    @api.depends('product_id.display_name')
+    def _compute_name_short(self):
+        """ Compute a short name for this sale order line, to be used on the website where we don't have much space.
+            To keep it short, instead of using the first line of the description, we take the product name without the internal reference.
+        """
+        for record in self:
+            record.name_short = record.product_id.with_context(display_default_code=False).display_name
+
+    def get_description_following_lines(self):
+        return self.name.splitlines()[1:]
diff --git a/addons/website_sale/views/templates.xml b/addons/website_sale/views/templates.xml
index 20a4c211015..1d5010bc412 100644
--- a/addons/website_sale/views/templates.xml
+++ b/addons/website_sale/views/templates.xml
@@ -817,6 +817,24 @@
         </xpath>
     </template>
 
+    <!-- We use this template where we want to give the user a link to the product of a sale order line. -->
+    <template id="cart_line_product_link" name="Shopping Cart Line Product Link">
+        <a t-attf-href="/shop/product/#{ slug(line.product_id.product_tmpl_id) }">
+            <t t-raw="0"/>
+        </a>
+    </template>
+
+    <!-- This template displays all the lines following the first one on the description of the sale order line, with a muted style. For typical products this content will be the product description_sale. -->
+    <template id="cart_line_description_following_lines" name="Shopping Cart Line Description Following Lines">
+        <div t-if="line.get_description_following_lines()" t-attf-class="text-muted {{div_class}} small">
+            <t t-foreach="line.get_description_following_lines()" t-as="name_line">
+                <span><t t-esc="name_line"/></span>
+                <br t-if="not name_line_last" />
+            </t>
+        </div>
+    </template>
+
+    <!-- This template is the one at the "Review order" step (the first one) on the checkout workflow. -->
     <template id="cart_lines" name="Shopping Cart Lines">
         <div t-if="not website_sale_order or not website_sale_order.website_order_line" class="js_cart_lines alert alert-info">
           Your cart is empty!
@@ -840,15 +858,13 @@
                         </td>
                         <td t-if="line.product_id.product_tmpl_id" class='td-product_name'>
                             <div>
-                                <a t-attf-href="/shop/product/#{ slug(line.product_id.product_tmpl_id) }">
-                                    <strong t-esc="line.product_id.with_context(display_default_code=False).display_name" />
-                                </a>
-                            </div>
-                            <div class="text-muted d-none d-md-block small">
-                                <t t-foreach="line.name.splitlines()[1:]" t-as="name_line">
-                                    <span><t t-esc="name_line"/></span><br/>
+                                <t t-call="website_sale.cart_line_product_link">
+                                    <strong t-field="line.name_short" />
                                 </t>
                             </div>
+                            <t t-call="website_sale.cart_line_description_following_lines">
+                                <t t-set="div_class" t-value="'d-none d-md-block'"/>
+                            </t>
                         </td>
                         <td class="text-center td-qty">
                             <div class="css_quantity input-group oe_website_spinner">
@@ -943,6 +959,7 @@
         </t>
     </template>
 
+    <!-- this template is the one when we mouse over "My Cart" on the top right -->
     <template id="cart_popover" name="Cart Popover">
         <div t-if="not website_sale_order or not website_sale_order.website_order_line" class="alert alert-info">
           Your cart is empty!
@@ -954,10 +971,11 @@
                         <span t-field="line.product_id.image_small" t-options="{'widget': 'image', 'class': 'rounded'}" />
                     </div>
                     <div class="col-9">
-                        <a t-attf-href="/shop/product/#{ slug(line.product_id.product_tmpl_id) }">
-                            <span t-esc="line.product_id.with_context(display_default_code=False).display_name" class="h6" />
-                        </a>
-                        <br />
+                        <div>
+                            <t t-call="website_sale.cart_line_product_link">
+                                <span class="h6" t-esc="line.name_short" />
+                            </t>
+                        </div>
                         <small>Qty: <t t-esc="int(line.product_uom_qty) == line.product_uom_qty and int(line.product_uom_qty) or line.product_uom_qty" /></small>
                     </div>
                 </div>
@@ -1388,6 +1406,10 @@
         </div>
     </template>
 
+    <!-- This template is the one present on the right during the payment process.
+        Here it is important to not show too much information to the user, because we want him to pay!
+        We shouldn't display link to products or long descriptions.
+    -->
     <template id="cart_summary" name="Cart right column">
         <div class="card">
             <div class="card-body p-xl-0">
@@ -1416,9 +1438,9 @@
                                 </td>
                                 <td class='td-product_name' t-if="line.product_id.product_tmpl_id">
                                     <div>
-                                        <strong t-field="line.product_id.with_context(display_default_code=False).display_name" />
+                                        <strong t-field="line.name_short" />
                                     </div>
-                           </td>
+                                </td>
                                 <td class='td-qty'>
                                     <div t-esc="line.product_uom_qty" />
                                 </td>