Need help explaining in-addr.arpa to Limelight

Hi, I seem to be having a problem. Limelight has SWIP'd 69.28.185.0/24 to me, and I asked for IN-ADDR.ARPA control. I recently went to check and it seemed not to be working right. I sent them an email around 11p Eastern Sunday nite asking it to be fixed. I even included a reference to a web page on how to delegate in-addr.arpa. I received the following back : "This is done, but you will need to rename the zone on your end to: tboh.185.28.69.in-addr.arpa." Is there someone out there that might be able to help me explain this to the techs there. That you can't "subdomain" an in-addr.arpa like you do a domain name? Thanks, Tuc/TBOH