diff --git a/addons/base_geolocalize/models/res_config_settings.py b/addons/base_geolocalize/models/res_config_settings.py
index 4cd6cdb87da..5cef30c5472 100644
--- a/addons/base_geolocalize/models/res_config_settings.py
+++ b/addons/base_geolocalize/models/res_config_settings.py
@@ -13,7 +13,7 @@ class ResConfigSettings(models.TransientModel):
         config_parameter='base_geolocalize.geo_provider',
         default=lambda x: x.env['base.geocoder']._get_provider()
     )
-    geoloc_provider_techname = fields.Char(related='geoloc_provider_id.tech_name', readonly=1)
+    geoloc_provider_techname = fields.Char(related='geoloc_provider_id.tech_name', readonly=True)
     geoloc_provider_googlemap_key = fields.Char(
         string='Google Map API Key',
         config_parameter='base_geolocalize.google_map_api_key',
diff --git a/addons/hr_holidays/models/hr_leave_accrual_plan_level.py b/addons/hr_holidays/models/hr_leave_accrual_plan_level.py
index f31bcc0b1fa..0859e42ffc6 100644
--- a/addons/hr_holidays/models/hr_leave_accrual_plan_level.py
+++ b/addons/hr_holidays/models/hr_leave_accrual_plan_level.py
@@ -120,7 +120,7 @@ class AccrualPlanLevel(models.Model):
         [('postponed', 'Transferred to the next year'),
          ('lost', 'Lost')],
         string="At the end of the calendar year, unused accruals will be",
-        default='postponed', required='True')
+        default='postponed', required=True)
     postpone_max_days = fields.Integer("Maximum amount of accruals to transfer",
         help="Set a maximum of days an allocation keeps at the end of the year. 0 for no limit.")
 
diff --git a/addons/iap/models/iap_account.py b/addons/iap/models/iap_account.py
index 739d4230635..b1f87a1c663 100644
--- a/addons/iap/models/iap_account.py
+++ b/addons/iap/models/iap_account.py
@@ -31,7 +31,7 @@ class IapAccount(models.Model):
         'iap.account.info', compute='_compute_info', inverse='_inverse_info', search='_search_info')
     account_info_ids = fields.One2many(
         'iap.account.info', 'account_id',
-        invisible=True, string="Accounts from IAP")
+        string="Accounts from IAP")
     balance = fields.Char(compute='_compute_balance')
     description = fields.Char(related='account_info_id.description')
     warn_me = fields.Boolean(
@@ -247,7 +247,7 @@ class IAPAccountInfo(models.TransientModel):
     account_id = fields.Many2one('iap.account', string='IAP Account')
     account_token = fields.Char()
     balance = fields.Float(string='Balance', digits=(16, 4), default=0)
-    account_uuid_hashed = fields.Char(string='Account UUID', invisible=True)
+    account_uuid_hashed = fields.Char(string='Account UUID')
     service_name = fields.Char(string='Related Service')
     description = fields.Char()
     warn_me = fields.Boolean('Warn me', default=False)
diff --git a/addons/mail/models/mail_mail.py b/addons/mail/models/mail_mail.py
index 5ad42341b2a..cae5291b7cb 100644
--- a/addons/mail/models/mail_mail.py
+++ b/addons/mail/models/mail_mail.py
@@ -46,7 +46,7 @@ class MailMail(models.Model):
     mail_message_id_int = fields.Integer(compute='_compute_mail_message_id_int', compute_sudo=True)
     body_html = fields.Text('Text Contents', help="Rich-text/HTML message")
     body_content = fields.Html('Rich-text Contents', sanitize=True, compute='_compute_body_content', search="_search_body_content")
-    references = fields.Text('References', help='Message references, such as identifiers of previous messages', readonly=1)
+    references = fields.Text('References', help='Message references, such as identifiers of previous messages', readonly=True)
     headers = fields.Text('Headers', copy=False)
     restricted_attachment_count = fields.Integer('Restricted attachments', compute='_compute_restricted_attachments')
     unrestricted_attachment_ids = fields.Many2many('ir.attachment', string='Unrestricted Attachments',
@@ -81,7 +81,7 @@ class MailMail(models.Model):
         ("mail_dup", "Duplicated Email"),
         ], string='Failure type')
     failure_reason = fields.Text(
-        'Failure Reason', readonly=1, copy=False,
+        'Failure Reason', readonly=True, copy=False,
         help="Failure reason. This is usually the exception thrown by the email server, stored to ease the debugging of mailing issues.")
     auto_delete = fields.Boolean(
         'Auto Delete',
diff --git a/addons/mail/models/mail_message.py b/addons/mail/models/mail_message.py
index b956e26c534..08166eb11f5 100644
--- a/addons/mail/models/mail_message.py
+++ b/addons/mail/models/mail_message.py
@@ -163,7 +163,7 @@ class Message(models.Model):
     reply_to_force_new = fields.Boolean(
         'No threading for answers',
         help='If true, answers do not go in the original document discussion thread. Instead, it will check for the reply_to in tracking message-id and redirected accordingly. This has an impact on the generated message-id.')
-    message_id = fields.Char('Message-Id', help='Message unique identifier', index='btree', readonly=1, copy=False)
+    message_id = fields.Char('Message-Id', help='Message unique identifier', index='btree', readonly=True, copy=False)
     reply_to = fields.Char('Reply-To', help='Reply email address. Setting the reply_to bypasses the automatic thread creation.')
     mail_server_id = fields.Many2one('ir.mail_server', 'Outgoing mail server')
     # keep notification layout informations to be able to generate mail again
diff --git a/addons/mail/models/mail_thread_blacklist.py b/addons/mail/models/mail_thread_blacklist.py
index c7c32fc1b4f..4ce6752c805 100644
--- a/addons/mail/models/mail_thread_blacklist.py
+++ b/addons/mail/models/mail_thread_blacklist.py
@@ -31,8 +31,7 @@ class MailBlackListMixin(models.AbstractModel):
     _primary_email = 'email'
 
     email_normalized = fields.Char(
-        string='Normalized Email', compute="_compute_email_normalized", compute_sudo=True,
-        store=True, invisible=True,
+        string='Normalized Email', compute="_compute_email_normalized", compute_sudo=True, store=True,
         help="This field is used to search on email address as the primary email field can contain more than strictly an email address.")
     # Note : is_blacklisted sould only be used for display. As the compute is not depending on the blacklist,
     # once read, it won't be re-computed again if the blacklist is modified in the same request.
diff --git a/addons/mail/models/mail_tracking_value.py b/addons/mail/models/mail_tracking_value.py
index dda8ad0fb30..0a157f81dab 100644
--- a/addons/mail/models/mail_tracking_value.py
+++ b/addons/mail/models/mail_tracking_value.py
@@ -12,31 +12,31 @@ class MailTracking(models.Model):
     _rec_name = 'field'
     _order = 'tracking_sequence asc'
 
-    field = fields.Many2one('ir.model.fields', required=True, readonly=1, index=True, ondelete='cascade')
-    field_desc = fields.Char('Field Description', required=True, readonly=1)
+    field = fields.Many2one('ir.model.fields', required=True, readonly=True, index=True, ondelete='cascade')
+    field_desc = fields.Char('Field Description', required=True, readonly=True)
     field_type = fields.Char('Field Type')
     field_groups = fields.Char(compute='_compute_field_groups')
 
-    old_value_integer = fields.Integer('Old Value Integer', readonly=1)
-    old_value_float = fields.Float('Old Value Float', readonly=1)
-    old_value_monetary = fields.Float('Old Value Monetary', readonly=1)
-    old_value_char = fields.Char('Old Value Char', readonly=1)
-    old_value_text = fields.Text('Old Value Text', readonly=1)
-    old_value_datetime = fields.Datetime('Old Value DateTime', readonly=1)
+    old_value_integer = fields.Integer('Old Value Integer', readonly=True)
+    old_value_float = fields.Float('Old Value Float', readonly=True)
+    old_value_monetary = fields.Float('Old Value Monetary', readonly=True)
+    old_value_char = fields.Char('Old Value Char', readonly=True)
+    old_value_text = fields.Text('Old Value Text', readonly=True)
+    old_value_datetime = fields.Datetime('Old Value DateTime', readonly=True)
 
-    new_value_integer = fields.Integer('New Value Integer', readonly=1)
-    new_value_float = fields.Float('New Value Float', readonly=1)
-    new_value_monetary = fields.Float('New Value Monetary', readonly=1)
-    new_value_char = fields.Char('New Value Char', readonly=1)
-    new_value_text = fields.Text('New Value Text', readonly=1)
-    new_value_datetime = fields.Datetime('New Value Datetime', readonly=1)
+    new_value_integer = fields.Integer('New Value Integer', readonly=True)
+    new_value_float = fields.Float('New Value Float', readonly=True)
+    new_value_monetary = fields.Float('New Value Monetary', readonly=True)
+    new_value_char = fields.Char('New Value Char', readonly=True)
+    new_value_text = fields.Text('New Value Text', readonly=True)
+    new_value_datetime = fields.Datetime('New Value Datetime', readonly=True)
 
     currency_id = fields.Many2one('res.currency', 'Currency', readonly=True, ondelete='set null',
         help="Used to display the currency when tracking monetary values")
 
     mail_message_id = fields.Many2one('mail.message', 'Message ID', required=True, index=True, ondelete='cascade')
 
-    tracking_sequence = fields.Integer('Tracking field sequence', readonly=1, default=100)
+    tracking_sequence = fields.Integer('Tracking field sequence', readonly=True, default=100)
 
     @api.depends('mail_message_id', 'field')
     def _compute_field_groups(self):
diff --git a/addons/purchase/models/purchase.py b/addons/purchase/models/purchase.py
index 7a2cfc4d47e..ad1f9dd5372 100644
--- a/addons/purchase/models/purchase.py
+++ b/addons/purchase/models/purchase.py
@@ -92,7 +92,7 @@ class PurchaseOrder(models.Model):
              "delivery order sent by your vendor.")
     date_order = fields.Datetime('Order Deadline', required=True, states=READONLY_STATES, index=True, copy=False, default=fields.Datetime.now,
         help="Depicts the date within which the Quotation should be confirmed and converted into a purchase order.")
-    date_approve = fields.Datetime('Confirmation Date', readonly=1, index=True, copy=False)
+    date_approve = fields.Datetime('Confirmation Date', readonly=True, index=True, copy=False)
     partner_id = fields.Many2one('res.partner', string='Vendor', required=True, states=READONLY_STATES, change_default=True, tracking=True, domain="['|', ('company_id', '=', False), ('company_id', '=', company_id)]", help="You can find a vendor by its Name, TIN, Email or Internal Reference.")
     dest_address_id = fields.Many2one('res.partner', domain="['|', ('company_id', '=', False), ('company_id', '=', company_id)]", string='Dropship Address', states=READONLY_STATES,
         help="Put an address if you want to deliver directly from the vendor to the customer. "
diff --git a/addons/repair/models/stock_picking.py b/addons/repair/models/stock_picking.py
index 9ab65278513..f3cd6b974db 100644
--- a/addons/repair/models/stock_picking.py
+++ b/addons/repair/models/stock_picking.py
@@ -21,8 +21,7 @@ class PickingType(models.Model):
     count_repair_late = fields.Integer(
         string="Number of Repair Orders Late", compute='_compute_count_repair')
 
-    default_location_dest_id = fields.Many2one(
-        readonly={"code", "=", "repair_operation"})
+    default_location_dest_id = fields.Many2one()
     default_remove_location_dest_id = fields.Many2one(
         'stock.location', 'Default Remove Destination Location',
         check_company=True, readonly=True,
diff --git a/addons/resource/models/resource_calendar.py b/addons/resource/models/resource_calendar.py
index 57094969adf..d0775f553f4 100644
--- a/addons/resource/models/resource_calendar.py
+++ b/addons/resource/models/resource_calendar.py
@@ -98,7 +98,7 @@ class ResourceCalendar(models.Model):
         _tz_get, string='Timezone', required=True,
         default=lambda self: self._context.get('tz') or self.env.user.tz or self.env.ref('base.user_admin').tz or 'UTC',
         help="This field is used in order to define in which timezone the resources will work.")
-    tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset', invisible=True)
+    tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset')
     two_weeks_calendar = fields.Boolean(string="Calendar in 2 weeks mode")
     two_weeks_explanation = fields.Char('Explanation', compute="_compute_two_weeks_explanation")
 
diff --git a/addons/sms/wizard/sms_resend.py b/addons/sms/wizard/sms_resend.py
index ff8f86deb99..f581c78ea82 100644
--- a/addons/sms/wizard/sms_resend.py
+++ b/addons/sms/wizard/sms_resend.py
@@ -15,7 +15,7 @@ class SMSRecipient(models.TransientModel):
     failure_type = fields.Selection(
         related='notification_id.failure_type', string='Error Message', related_sudo=True, readonly=True)
     partner_id = fields.Many2one('res.partner', 'Partner', related='notification_id.res_partner_id', readonly=True)
-    partner_name = fields.Char(string='Recipient Name', readonly='True')
+    partner_name = fields.Char(string='Recipient Name', readonly=True)
     sms_number = fields.Char(string='Phone Number')
 
 
diff --git a/addons/test_website/models/model.py b/addons/test_website/models/model.py
index 375e906b085..33c19f386ec 100644
--- a/addons/test_website/models/model.py
+++ b/addons/test_website/models/model.py
@@ -15,7 +15,7 @@ class TestModel(models.Model):
     ]
     _description = 'Website Model Test'
 
-    name = fields.Char(required=1)
+    name = fields.Char(required=True)
 
     @api.model
     def _search_get_detail(self, website, order, options):
diff --git a/odoo/addons/base/models/res_partner.py b/odoo/addons/base/models/res_partner.py
index 207a1933c6f..e63d2cae079 100644
--- a/odoo/addons/base/models/res_partner.py
+++ b/odoo/addons/base/models/res_partner.py
@@ -206,7 +206,7 @@ class Partner(models.Model):
                                "If the timezone is not set, UTC (Coordinated Universal Time) is used.\n"
                                "Anywhere else, time values are computed according to the time offset of your web client.")
 
-    tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset', invisible=True)
+    tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset')
     user_id = fields.Many2one(
         'res.users', string='Salesperson',
         compute='_compute_user_id',
diff --git a/odoo/addons/base/models/res_users.py b/odoo/addons/base/models/res_users.py
index b9d26496dd6..2e69fe3d8ca 100644
--- a/odoo/addons/base/models/res_users.py
+++ b/odoo/addons/base/models/res_users.py
@@ -309,8 +309,7 @@ class Users(models.Model):
         string='Related Partner', help='Partner-related data of the user')
     login = fields.Char(required=True, help="Used to log into the system")
     password = fields.Char(
-        compute='_compute_password', inverse='_set_password',
-        invisible=True, copy=False,
+        compute='_compute_password', inverse='_set_password', copy=False,
         help="Keep empty if you don't want the user to be able to connect on the system.")
     new_password = fields.Char(string='Set Password',
         compute='_compute_password', inverse='_set_new_password',
@@ -328,7 +327,7 @@ class Users(models.Model):
     share = fields.Boolean(compute='_compute_share', compute_sudo=True, string='Share User', store=True,
          help="External user with limited access, created only for the purpose of sharing data.")
     companies_count = fields.Integer(compute='_compute_companies_count', string="Number of Companies")
-    tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset', invisible=True)
+    tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset')
     res_users_settings_ids = fields.One2many('res.users.settings', 'user_id')
     # Provide a target for relateds that is not a x2Many field.
     res_users_settings_id = fields.Many2one('res.users.settings', string="Settings", compute='_compute_res_users_settings_id', search='_search_res_users_settings_id')
diff --git a/odoo/fields.py b/odoo/fields.py
index 82d15b37492..b786688a63b 100644
--- a/odoo/fields.py
+++ b/odoo/fields.py
@@ -163,7 +163,7 @@ class Field(MetaField('DummyField', (object,), {})):
     :type default: value or callable
 
     :param dict states: a dictionary mapping state values to lists of UI attribute-value
-        pairs; possible attributes are: ``readonly``, ``required``, ``invisible``.
+        pairs; possible attributes are: ``readonly``, ``required``.
 
         .. warning:: Any state-based condition requires the ``state`` field value to be
             available on the client-side UI. This is typically done by including it in
@@ -318,7 +318,6 @@ class Field(MetaField('DummyField', (object,), {})):
 
     string = None                       # field label
     help = None                         # field tooltip
-    invisible = False                   # whether the field is invisible
     readonly = False                    # whether the field is readonly
     required = False                    # whether the field is required
     states = None                       # set readonly and required depending on state
@@ -538,6 +537,12 @@ class Field(MetaField('DummyField', (object,), {})):
             else:
                 self.setup_nonrelated(model)
 
+            if not isinstance(self.required, bool):
+                warnings.warn(f'Property {self}.required should be a boolean ({self.required}).')
+
+            if not isinstance(self.readonly, bool):
+                warnings.warn(f'Property {self}.readonly should be a boolean ({self.readonly}).')
+
             if self.states:
                 warnings.warn(f'"states" property on the field "{self}" is no longer used', DeprecationWarning)