We recently completed development on some fixes and feature enhancements to the Crossref REST API. Soon, special characters will no longer be removed from DOIs during ingestion to the REST API, markup will be retained in titles, and resource URLs will be included in the JSON response.
In order to realize these changes across those records affected by these improvements, we will be scanning for and reindexing affected DOIs. We generally recommend you use the indexed date to retrieve periodic, incremental metadata updates. If you do, you will notice an increased number of reindexed records over the next few weeks.
Please reply here or contact us at firstname.lastname@example.org with any questions.