Expired listings refer to properties that:

Expired listings specifically denote properties that were listed for sale but did not sell within the time frame of the listing agreement. This usually means the property did not attract sufficient interest from buyers to close a sale before the listing period ended. Hence, these listings become "expired," and the property is no longer actively for sale under that agreement.

Properties sold at auction, currently in foreclosure, or those with accepted offers do not fall into this category because they represent different stages or outcomes of the real estate transaction process. An auction indicates an aggressive selling method, foreclosure indicates legal procedures for reclaiming property due to non-payment, and an accepted offer suggests that the property is currently in a transaction process. Thus, the unique aspect of expired listings is that they represent an unsuccessful attempt to sell, which is directly captured by the description of being listed but not sold.