My understanding is that the segments aren't actually deleted, ust marked as deleted and therefore continue to work where being used .. HOWEVER ... if you edit a request (ReportBuilder) a unhelpful message is shown 'Inaccessible/deleted segment' along with a long alphanumeric identifier .. if the request is edited the deleted segment is automatically removed.
1. As the inaccessible/deleted segment is not referenced by name it could be very difficult to establish what the deleted segment did and how it was structured.
2. There is no admin UI that allows for the segment to be looked up which would either allow for it to be undeleted (preferred) or review the definition so that it can be duplicated.
Update : Segment had not been deleted but was inaccessible because the segment in question had not been shared with user editing the request. So in addition to the above request the error message should make a clear distinction between not shared segments and deleted along with being able to identify the segment in question
