Possible events where patron notification may be desired.
Checkouts - Digital receipt type functionality
Checkins - Digital receipt, those that want to know that the library really received their returned items.
Renewal - Digital receipt.
Almost Due - Reminder service, configurable by number of days/hours before item is due.
Due
Overdue (1st , 2nd, Nth overdue)
Billed (1st, 2nd, Nth Bill)
Customer Record Expired - or about to expire. Tied into online renewal form. "Please renew so your access to Library services are not interrupted"
Item placed on hold - Digital receipt. Daily summary.
Item available for pickup.
Item available on shelf - Notify when hold placed on item that is at a customers library. Item is available on shelf, you can pick it up at any time.
Item no longer available on shelf - Notify when item is no longer available on shelf, customer will be notified again when it is available.
Hold Fulfillment issue - Item not being filled in a timely manner, suggest trying an alternative format.
Hold canceled - Hold has been canceled for various reasons.
Item Recalled - someone more important than you needs this item :)
Fines Owed, over a certain amount(customer preference or Libraries)
New item by watched author, series, search - might duplicate rss feeds.
Customer Record Changed (Account Added=>Welcome Message, Account Expired=>Notification)
Fines or Bills paid
Notification method failed(Send email if SMS failed "We tried to text you, but we had a problem, please make sure we have your correct information".)
Staff Placed email, both on individual patrons, and for groups of patrons.
Item being mailed to customer, if library supports that method.
Account Information change - Change in account information, address change, email change, etc.
Stored balance change - if customer has a stored balance on their account.