Creating collections is possible through both typing the barcodes(or full ids) of manifests manually or using the provided search functionality. These two options can be combined. Currently created collections are saved into the cookies and will be lost after the browser is closed. Therefore you can't edit or delete them yet. In the future, when SACHA has a login system, you will be able to save, edit and delete your personal collections. For more information, you can read the documentation.