What exactly a client gets from Airbnb when the booking is completed?

[Zdenek0]

I would like to know what exactly a client gets from Airbnb when  the booking is completed, I mean, with the voucher that they get. 

I do not know how they get all the instruccions, because all the information about contact information, how to get to the property, phones numbers etc,is written on the profile visible for the customers but for any reason when the booking is completed the guests keep asking about that basic information. 

If I want to write a contact's phone numbers on the voucher that is sent to the customers can I do it in any way? I ask because I tried but on the web side It was hidden. 

Thanks