Description 

What produces "hold-request-filled" / "item-available" letters?  Are  ue_06 and/or the cir-12 Service involved?

Resolution 

The ue_06 request daemon and the cir-12 ("Call Slips for Requests") Service only produce call slips and request-not-available letters, they don't produce request-available letters.

As described in the z37.pdf document, z37_status "S" indicates:  "Hold Shelf - Request has been trapped, patron has been notified that the requested material is ready to be picked up."

The program which sends "item-available" letters and sets the z37_status to "S" is the execute_hold_request program.

The two programs which call execute_hold_request are b_cir_06_d and pc_cir_c0429.   b_cir_06_d is part of the cir-06 ("Hold Shelf Report") batch Service.  pc_cir_c0429 is the "Create a Hold Request Filled Letter and Loan Item if Delivery"  online program.   

(cir-06 "enables you to identify items that have been on the hold shelf for a particular number of days, and to print a letter to the patron informing him that the item is no longer being held for him."  And to send an item-available notice to the next patron in the queue.  It does not send a letter to the original requester; only pc_cir_c0429 does that.)