Hi, Wildfire8470, and welcome to MobileRead.
To answer your question, the condensed URLs forbidden by the Guidelines are regular links that have been run through a URL shortening service. For example, the Wikipedia entry for Superman is http://en.wikipedia.org/wiki/Superman. That same link, run through
Google's URL shortener becomes http://goo.gl/yv4s. At MobileRead, http://en.wikipedia.org/wiki/Superman/ is an allowed link, but http://goo.gl/yv4s is forbidden, even though they take you to the same destination.
There are a few special rules for authors here also. You can read them at
Promotion Posting Guidelines and
Rules for posting affiliate links in this forum.
And thanks, by the way, for taking the time to read the Guidelines!