If the StoreHouse goods were used in documents, layouts, sets or price lists, then it cannot be deleted from the database.
If you need to stop using the goods, i.e. mark as unused, then you can create a group (groups) of goods with the Deleted Goods flag and transfer unused goods to such groups.
Goods imported from r_keeper do not need to be manually moved to a group with the Deleted Goods flag. If a dish is removed from sale at the cash stations, i.e. deleted in r_keeper, then when imported into StoreHouse, the goods will automatically be placed in a special Restaurant menu > Deleted group, which also has the Deleted Goods flag set in the group properties
The group with the Deleted Goods flag and the goods included in this group are displayed in gray font in the list of goods.
The goods from the group with the Deleted Goods flag will be also displayed in gray font when searching for goods, if the In the Deleted group flag is set.