We have recently discovered an issue in the REST API where some relationships were not included in metadata records. These were ‘reciprocal’ relationships that were first asserted in a different record. For example, a preprint might be deposited with an is-preprint-of relationship, linking it to an article. In the article we add a reciprocal has-preprint relationship. In the past, these were included in REST API metadata but were inadvertently removed in around November last year.
We have located the source of the problem and are now re-adding all of the missing relationships. This process will be complete by the end of March, meaning they will be included in the next monthly snapshot for Metadata Plus subscribers.
There is a further step that we will need to complete, to automatically reindex works with a reciprocal relationship. Until that is finished, users may notice some new relationship in which the reciprocal assertion is missing. We apologise for any inconvenience or confusion caused by the disappearance and reappearance of this metadata.