Item Statuses in Koha

notforloan

 Item is not available for loan  (overrides
 biblio-level and item-level itemtype)
 NOT_LOAN authorized value
 default values are:
 -1 (ordered)
 0 (not notforloan)
 1 (Not for loan)
 2 (Staff Collection)

 A negative value indicates that the item can be placed on hold, but may not circulate.

damaged

 Item's Damaged status
 DAMAGED authorized value
 default values are 0 (not damaged) and 1 (Damaged)
 negative values would indicate 'not damaged'

itemlost

 Item's Lost status
 LOST authorized value
 default values are:
 0 Not Lost
 1 Lost
 2 Long Overdue,
 3 Lost and Paid For
 4 Missing in Inventory
 5 Missing in Holdqueue
 
 negative value would indicate 'not lost'

wthdrawn

 Item's Withdrawn status
 WITHDRAWN authorized value
 default values are:
 0 (not withdrawn)
 1 (Withdrawn)
 
 negative values mean 'not withdrawn'

onloan (date)

 Item is on loan, NULL means 'not on loan', date in
 format yyyy-mm-dd means 'on loan until date indicated'