Is Chris- a short form of Christopher?
A gentleman named Christopher signed Chris- in the email he wrote to me. When I reply him, what should I address him? Is Chris- OK? What's the function of "-"? A sign of abbreviation? I haven't seen it in people's names before.
P.S. He is in a higher position, so I want to show my respect to him. I used to call him Dr. + his last name.
Thank you!

Question

Is Chris- a short form of Christopher?
A gentleman named Christopher signed Chris- in the email he wrote to me. When I reply him, what should I address him? Is Chris- OK? What's the function of "-"? A sign of abbreviation? I haven't seen it in people's names before. 
P.S. He is in a higher position, so I want to show my respect to him. I used to call him Dr. + his last name. 
Thank you!

Answer

Agree with Mudy

Answer

Yeah it's right that Chris is a short form of Christopher. 
But it's very polite to address a person by using his full name if he or she is on a higher position. For example if u have to address him, u should write Dr. Christopher.

Answer

Yes :D

Answer

Yes, Chris is a shortened form of Christopher

Answer

If he is a Dr. then it's fine to address him as a doctor. Yes, Chris is a shortened version of Christopher, I think he probably meant to sign it as

-Chris

Which you usually do at the end of a letter or message and basically just signifies the persons name from my understanding.