odoo-event-addons/event_type_description/models/event_type.py

from odoo import models, fields
from odoo.tools import is_html_empty
from odoo.tools.translate import html_translate


class EventType(models.Model):
    _inherit = "event.type"

    description = fields.Html(
        string="Description",
        translate=html_translate,
        sanitize_attributes=False,
        sanitize_form=False,
        default="",
    )

    def clear_description(self):
        self.write({"description": ""})