Content type remote event receivers
Remote event receivers can currently, in SharePoint Online, not be added to content types (https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.client.contenttype_members.aspx). This makes it somehow tedious to catch events that are fired from items of a specific content type is added/updated/deleted. Having the possibility to add an event receiver to a content type would make this scenario easier to implement.

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