It so happened that I left the domain name (the owner refused, gave all my details and said "do with him what you want"), which I pay for for the reason that subdomena work sites that I have created for their friends. Change the subdomain to something else would be extremely painful for everyone. Someone that has his own page, who is a small business card site.
The Internet except old articles about cybersquatting and Parking for 2008-2012 found nothing.
Advise how you can use this domain name (4-digit, not quite sure whether to mention the real name here (so secret, no)), what to do, maybe even be able to recoup it, it would be ideal.