. Real estate listings held by brokerage firms other than United Real Estate Louisville may be marked with the Internet Data Exchange logo and detailed information about those properties will include the name of the listing broker(s) when required by the MLS. All rights reserved. Show More... The data relating to real estate for sale on this web site comes in part from the Internet Data Exchange Program. Real estate listings held by IDX Brokerage firms other than United Real Estate Louisville are marked with the Internet Data Exchange logo or the Internet Data Exchange thumbnail logo and detailed information about them includes the name of the listing IDX Brokers. 