Metadata error Custom license & Open data

[eduardklap]

Is there an existing bug report for this?

• I have searched the existing bug reports

Current Behavior

Combining custom license with open data leads to an error from DataCite.

Expected Behavior

Multiple options:

• a warning or error message that it is better to add an open license (like CC-BY) to an open dataset
• a warning before publishing
• an option to specify an url with the custom license that can be used to populate the rightsURI field

Steps to Reproduce

1. Combine the following options in Yoda default-3 metadata schema:

"Data_Access_Restriction": "Open - freely retrievable",
"License": "Custom"

2. Publish the collection, it will create the following fields in the Datacite JSON:

"rightsList": [
                {
                    "rights": "Open - freely retrievable",
                    "rightsUri": "info:eu-repo/semantics/openAccess"
                },
                {
                    "rights": "Custom",
                    "rightsUri": "https://surf-data.irods.surfsara.nl:9443/vault-etk-testing/research-etk-testing[1762524484]"                }
            ]

3. The "rightsUri" field will be populated with the Yoda web address for the Vault collection, which includes square brackets for the Unix epoch. This will lead to an error when trying to publish the dataset (tested at https://support.datacite.org/reference/post_dois):

"errors": [
    {
      "source": "rights', attribute 'rightsURI",
      "title": "DOI prefix/suffix: 'https://surf-data.irods.surfsara.nl:9443/vault-etk-testing/research-etk-testing[1762524484]' is not a valid value of the atomic type 'xs:anyURI'. at line 18, column 0",
      "uid": "prefix/suffix"
    }

Environment

- Yoda version v2.0.0

Additional Context

Strangely enough, there has been at least one dataset published in the past, with the same square brackets in the rightsURI in the datacite JSON: https://publication.yoda.wur.nl/full/WUR01/BSY8ZN.html
Since then, Yoda has been upgraded but as far as I can see there were no changes at the Datacite side (both metadata v4.6).
Is there a validation step in Yoda built in for the Datacite metadata? In that case, would it be an option to include a validation for this?