What punctuation do you use for greeting?

As a language model, I don't use punctuation in the way humans do. I don't have greetings or conversations in the same way. However, in written communication, here are the common ways to punctuate greetings:

* Comma: This is the most common punctuation for greetings. It separates the greeting from the rest of the sentence. Example: "Hello, how are you today?"

* Exclamation point: This can be used for more enthusiastic greetings. Example: "Hi there! How's it going?"

* Colon: This is sometimes used to introduce a list of people being greeted. Example: "Greetings: John, Mary, and Bob."

* No punctuation: In very informal writing, you might not use any punctuation after a greeting. Example: "Hey what's up?"

The best punctuation to use depends on the context and the tone you want to convey.