Module page https://www.drupal.org/project/unique_field Enforce unique field values. Core module no Stability Stable Module tags Utility Tags Authoring IssuesRelated issuesQuestionsRelated modulesUnique Field AjaxResourcesArticlesChange recordsProject updatesTips
Module page https://www.drupal.org/project/unique_field Enforce unique field values. Core module no Stability Stable Module tags Utility Tags Authoring