Most metadata registered with Crossref is publicly available, including references.
A new reference distribution policy was adopted by the board in 2017 and came into effect on January 1st, 2018. Any member joining since then has their references set to ‘Open’ by default and included on our full list of members who have opened their references for distribution. Any member can choose to set their references to ‘Open’, ‘Limited’, or ‘Closed’ at any time. The policy can be set differently per DOI prefix.
When members elect to distribute references to the public, references included in the member's metadata records will be available through our metadata channels, including via the REST API and UNIXSD query results.
If you want to make all references publicly available (this is recommended) contact us and we'll enable reference distribution for your prefix (or prefixes). If you want to enable reference distribution for individual items, you can include a 'reference_distribution_opt' flag within your <journal_article> element, for example:
<journal_article publication_type="full_text" reference_distribution_opts="any">