Deleting lookup sets
Deleting a lookup set marks it as deleted but leaves it in the database. This is known as a logical deletion.
The 
		FSLOOKUPSET table contains a 
		Logical Delete field. When a
		user deletes a Lookup Set, the value of the 
		Logical Delete field becomes 
		1. All Lookup Sets with a 
		Logical Delete value of 
		1 are not displayed in the 
		Object Explorer.