Clean up duplicate content or other entities by merging them

There’s tools like Entity Merge meant for developers.

We added Simple Entity Merge to the new site and gave Site Managers the permissions needed to use it. It needs testing to ensure it does appropriately transfer references, but the goal is to avoid just that problem of tediously having to re-assign manually and then delete the now un-associated duplicates.

Also needed: reporting content or other entities that are not affiliated with anything, and listing entities that appear to possibly be duplicates.

The other angle for this is preventing the problem before it starts.

This is probably harder to do, but very beneficial with autocomplete giving content editors a better user experience of not having to re-enter data the system already has.

Autocomplete widget: Search existing items + Add new [#2940705] |

Entity Reference Field Widgets |

Historical: Combine “Add New” and “Add Existing” workflows [#2025457] |

Prioritize ‘add existing’ in nested entity creation UX to prevent duplication. [#2673548] |

entities - Inline Entity Form: alter autocomplete - Drupal Answers