Really? I did not know that. I guess here the Vladimirs put up with the contraction to Vlad as they're among the barbarians. ;-) Good to know though, thanks.
plenty of Vladimirs go by Vlad. Source: used to live in Russia
Never heard that someone named Vladimir shortened their name as Vlad. Live in Russia for 30 years. Most of the times you can call Vladimir as Vova. If you tell that your name is Vlad, everyone will think that you are Vladislav.