My lover received a short message from Greentree Inn: Welcome, please comment on the hotel. What does it mean to unsubscribe back to T?

This is a way to reply to text messages. For example, if you register any software with your mobile phone number, you will receive a message, and the reply is represented by letters such as T/N/D, and then you can choose to reply or not. Of course, if you don't want to receive hotel-related information in the future, you can reply directly, so that other hotels will not send similar information in the future.