What kind of sentence is "Please don't smoke"?

Imperative sentences

A sentence used to ask the listener to do something. Sentences such as commands, requests, prohibitions or dissuasion are all imperative sentences. Imperative sentences often ask others to do something or not to do something, with a period or exclamation point at the end of the sentence.

Imperative sentences expressing commands are affirmative and unwavering, and the first half of the sentence is often omitted. For example, "Stand at attention! Let's go!" "Take him away!"

The tone of the imperative sentence expressing the request is relatively gentle, such as Example 2. There are also imperative sentences like "Teacher, let me go!"

Imperative sentences expressing prohibition have a stronger tone, and most of them omit the first half of the sentence. For example, "Don't climb and break flowers and trees!" "No smoking!"

Imperative sentences expressing dissuasion are softer and have a discussion tone. Such as "Don't be late again!"