If the item you need isn't available, you don't have many options.
As noted by the FDLP handbook " If GPO is unable to fill a claim, your depository library may be able to acquire a needed publication through the Needs and Offers list."
If you decide not to pursue the item, or if you cannot obtain the item on the Needs and Offers list, then you need to go into the catalog and delete the item. Likewise, you will need to discard the Marcive labels.