Description:  Although the ESI has been removed from the primary storage system, it may still be accessible by the user with some delay in retrieval. Alternatively, a special IT or Legal custodian may have rights to retrieve ESI from the archive. Some Archival Systems are effectively Structured, while most systems retain some relational information such as date, owner and original location but no other real structured data. Almost all modern Archival Systems index the ESI for text searching, but few were designed for the level of accuracy and retrieval expected in discovery. The semi-structured nature of enterprise archives can dramatically increase the volume of potentially relevant ESI without enabling the responding party to find the truly relevant within the corpus.