IDX is essentially rules and enabling technologies allowing MLS participants to give
each other permission to display each others’ listings on their web sites; each
participant giving this permission also receives reciprocal permission from other
participants. Only the listings of participants who have not opted out of IDX can be
displayed on other participants’ sites. Display is subject to the rules of the
MLS(s). [From NAR's draft IDX Guide]
The National Association of REALTORS® has mandated that all local boards and
associations must make IDX available to their members:
"Associations of REALTORS" and their Multiple Listing Services are encouraged
to immediately, and must by January 1, 2002, enable MLS Participants to display on
Participants’ public websites aggregated MLS active listing information subject to
the requirements of state law and regulation. To comply with this requirement MLSs must,
if requested by a Participant, promptly provide basic “downloading” of current
listing information. Associations and MLSs can also offer alternative display options
including framing of Board, MLS, or other publicly-accessible sites displaying
Participants’ listings (with permission of the framed site). For purposes of this
policy, “downloading” means electronic transmission of data from MLS servers to
Participants’ servers. This policy does not require associations or MLSs to establish
publicly accessible sites displaying Participants’ listings."
