These were provided in a post from 10/2012. Search archives for "Semi-automated L3 interface DNS records".
https://gist.github.com/oogali/778830
http://cluepon.net/ras/generate_dnsptr_generic_php
Courtney Smith
courtneysmith@comcast.net
() ascii ribbon campaign - against html e-mail
/\ www.asciiribbon.org - against proprietary attachments