formal notice的用法和樣例：
例句
- Changing classes without formal approval will be deemed withdrawal from a course without formal notification.
在任何情況下，私自者轉班者將當退讀課程論，並不會有正式通知。 - Any State which makes a declaration under this Convention may withdraw it at any time by a formal notification in writing addressed to the depositary.
根據本公約規定做出聲明的任何國家可以隨時用書面正式通知保管人撤回該項聲明。
