This property is used to make a loadout store. Create a marker, give it this property, and set it to True. Once this is done, create [dromed:link:contains]] links from this marker to all of the items you wish your loadout to sell.
Make sure that all links object have the Inventory→Purchase Price property, or the player will be able to ‘buy’ them for free.
You also need to make sure that the mission’s entry in your StringsMissFlag.str file does not have no_loadout specified.
If you want to have custom items (such as tips) for sale in your shop, make sure to give them the the Inventory→Long Description property.
Property Name: ItemStore