What does "This item is marked for deletion" mean?

Some items in the catalog, especially parts, can be marked for deletion. An item is marked for deletion because it has either items for sale or items in orders tied to it and therefore cannot be deleted from the catalog right away. Once there are no more items for sale or items in orders tied to the catalog item, the item is purged from the catalog manually by a Catalog Administrator. On items that are marked for deletion, there will be a note with the reasoning behind this. Here is an example note on an item marked for deletion:
 

This Part is similar in mold type to the following Part(s):

  • Part 4616a Fabuland Airplane Motor / Engine Block, Small Pin Hole
  • Part 4616b Fabuland Airplane Motor / Engine Block, Technic Pin (3673) Hole - Set 6345
 
Item Marked for Deletion Restrictions:
 
  • Cannot be listed for sale (*)
  • Cannot be added to wanted list
  • Cannot be added to a new catalog inventory
  • Does not show in download of catalog items
* - An item marked for deletion can be still added to a store inventory via part-out (if the item still appears in a set inventory) and via a cancelled order where the item is returned from the order to the seller's inventory.
A link on the Catalog main page under "Other Catalog Features" shows all Items Currently Marked for Deletion.
 
Unreleased Sets:
 
On a rare occasion it may be discovered that a set in the catalog has not been released. If there is no proof of existence, the set is deleted from the catalog. If there is an image of that set, the set is not marked for deletion but is instead flagged as unreleased. In addition to having all the restrictions that an item marked for deletion item has, unreleased sets do not show in catalog search and browse results.
 
A link on the Catalog main page under "Other Catalog Features" shows all Unreleased Items.