1. SharePoint Event Handlers – Asynchronous Vs Synchronous

    www.fivenumber.com/sharepoint-event-handlers-asynchronous-vs...

    There is a little puzzlement among Asynchronousand Synchronous events, however I believe after reading this article, there will be no place for confusion in your ...

  2. Handle events in SharePoint Add-ins | Microsoft Docs

    https://docs.microsoft.com/.../handle-events-in-sharepoint-add-ins

    Note *These two new events may not be available in the Visual Studio UI. If not, pick ItemDeleting or ItemDeleted and then manually change the names.