When you are about to issue an item to a borrower and Horizon displays a dialogue box, take the time to check the actual wording before you decide to override the box.
Where the display says ‘Item is requested by [A], check it out to [B]’, click on YES and issue to the person in front of you. This item is likely to be from the open shelves with an uncollected IBDS REQUEST.
Where the display says ‘This item is being held for [A], do you want to check it out to [B]’, click on NO. This item is likely to be an ‘escaped’ HOLD i.e. separated from its hold slip and ending up on the open shelves instead of being corralled on the Hold Shelf.