/stændərd lɛtər/ – Phrase
Definition: Thư chuẩn
A more thorough explanation: a letter that a person, company, or institution always uses for a particular purpose. It is sent to more than one recipient with only minor changes to each letter (eg the date, the name of the recipient, the reference number etc).
Example: They sent us a standard letter that did not address our particular concerns in any way.