This knowledge is specialist knowledge for the Mournlands and Mourndares. It is fairly uncommon even amongst those who own Mourning items. Survivors of the Mourning who seek (and have the means to) to reclaim items from Old Cyre probably know of Abandonware, or learn about it quite quickly.

Abandonware

Abandonware are items magic items which have spent enough time in the Mournlands to absorb some of the latent magic fallout of the disaster. Abandonware is often referred to as Mourning Imparted Latent Dweomer (or MILD for short) by the houses.

If you are carrying more than one Abandonware item you have mild case of permeant nausea. Putting Abandonware items closer together, increases this nausea and moving them further away reduces it.

If you have been attuned to, carried or used more than one Abandonware item over the majority of a day the DM will ask you to roll a 1d100 to determine the effect. The more items you carry the worse this effect is.