I am going to show the vendor / customer name and phone number in to order PDF.
Just google and found some said it could be done by enabled the setting of Setup>PDF>Rules for address boxes “Show professional id with addresses - Professional ID 1/2/3/4/5/6”.
I don’t understand what you would like to do Customer name is already displayed on orders…
You have several hidden options that you can try :
PROPOSAL_AUTO_ADD_AUTHOR_AS_CONTACT ► Add Proposal Author as user contact follow proposal
DOC_SHOW_FIRST_SALES_REP ► Show the sales representant on header (at least on propal azur and rubis template)