Catalog/Inventory

When I run an inventory on the media in our Reference section, all of our media returns with an "invalid status". This is due to the fact that we choose to mark the copy as "unavailable." This is the only choice in Populi which will prohibit patrons from checking out these resources. Would you consider adding another choice which will mark the resource as available to patrons but not allow checkout of the media? Or, would you write code that will not mark "unavailable" as an "invalid status" in inventory??