Parsing MLS Lingo
One of the more confusing concepts on MLS is “Days on Market” vs. “CDOM” (Cumulative Days on Market) vs. “History.”
Initially, it’s pretty straightforward: after 30 days 
on the market, a given listing’s “Days on Market” is . . . surprise! . . . 30; CDOM is 30; and “History” shows one line, “Status: Active,” with the initial list date.
Trying Not to Look Stale
The complications ensue after a few months of market time, when listing agents will typically do what’s called a “cancel-and-relist” — often times in conjunction with a price reduction — to stimulate Buyer interest. (Or so I hear; all my listings sell for full price, right away. 🙂 ).
Assuming that that happens at 90 days, “Days on Market” would reset to zero, and CDOM would show “90.”
Meanwhile, under “History,” there would now be three lines: the initial “Active,” followed 
by “Cancel,” followed by “Active” and the new price.
Because “History” is the most complete archive, that’s typically what I check out first when I represent Buyers and want to know what’s going on.
So, even if a home has had multiple status changes, Realtors, and even been off the market for more than one year (which resets CDOM to zero), the “history” section will show all that.
Told ‘ya it was complicated . . .　
P.S.: Teresa Boardman’s St. Paul Real Estate Blog has a nice post showing what an especially brutal listing archive looks like.
