This page describes how you can package your data as a Darwin Core Archive (standard format for data publishing and sharing) in a Symbiota portal.
A Darwin Core Archive (DwC-A) is a data standard that is commonly used to package species occurrence data into a single, self-contained dataset. A DwC-A includes metadata, a file of occurrence data, and, often, files for determinations (identifications), images, and any other data extensions.
You can only publish a Darwin Core Archive of occurrences that have unique occurrence IDs and GUIDs. In your collection metadata page, make sure that you have selected a source for your GUID and that this source contains unique values for each occurrence.