Also there is no MLS, there are a lot of them.
It's a complete shit show as of 2013. Basically anything that is on any MLS I've seen is probably incorrect.
1. Try and get an offer before that window is up.
or
2. Put the listing up with enough wrong information that you get 2-3 more days to try and sell the property.
Apart from that, there's a lot of minor lying when it comes to these listings. Maybe the lot was 2 acres before it was subdivided, so you say on the listing that it's 2 acres. Maybe you jiggle the handle on the listing for the first week or so so it shows up as new/updated every day. Maybe you say that the listing has "central window unit AC" to try and confuse people into showing up.
It's mostly a lot of light treason against buyers and sellers. Real estate is a bit of a dogfight and much of it falls into the "technically illegal but not worth suing" bucket.