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Date updated: 5/12/2023

London Metropolitan Archives (LMA) exists to collect records of London’s rich past history and to find and collect records of London’s vibrant and diverse present, which are selected, catalogued, stored and permanently preserved for the use and benefit of present and future generations. The digital preservation policy has been created to support the long term use and preservation of digital records and documents.


This document specifies how City of London staff based at LMA will preserve and manage ‘digital archives’.

This policy and related guidance covers:

  1. Born digital files deposited under acquisitions procedure and held as originals by LMA
  2. Born digital files transferred under City of London Records Management procedure and held as originals for permanent preservation as part of the Archive of the City of London
  3. Digital surrogate/access copy files created from ‘original’ documents in any media (manuscript, photograph, map, video, audio, digital file etc...)

It should be noted that digital files created within LMA will only be preserved as part of the Trusted Digital Repository (TDR) if they are to be permanently retained.

Digital files designated for preservation in the TDR will be prepared for ingest on a secured server partition. Where necessary, files stored within the partition will be managed with tools including Droid and audited using spread sheets and other data collection tools.

The primary storage media for digital files preserved under this policy will be server-based hard disk storage maintained in appropriate environmental conditions.

Digital files to be preserved will be managed within structured, secured, dedicated folders on local and corporate servers. Full backup routines will be implemented to provide disaster recovery processes.

If the use of removable media is necessary, gold coated CD-R and DVD-R’s or Ultrium magnetic tape cartridges will be used and stored in an appropriate environment. Removable media will be checked annually for signs of physical deterioration and technical obsolescence. Migration onto new removable media will be carried out where deemed necessary to ensure continuing access to the digital files.

Files will be transferred from the secure partition to the TDR, LMA’s digital preservation system, for long term preservation.

LMA staff will prepare and ingest digital files as Submission Information Packages (SIPs); each raw digital asset will be processed to identify checksum information, extract technical data, and characterize the asset. Once ingestion is complete, the digital asset will be stored with its content, provenance, and preservation metadata as an Archive Information Package (AIP).

Access copies of ingested files are created by the TDR and will be linked to the Minisis M2A cataloguing system for staff use and the London Metropolitan Archives Collections Catalogue website for public use where appropriate.

Wherever possible, incoming files must be ‘open format’ or very widely used formats. Ideally, the original formatting within the document should be preserved. Acquisitions staff will ensure that all incoming deposits are checked for compatibility with our systems. If archive staff are unable to read the file with existing software, an alternative version should be requested from the depositor to be deposited alongside the original (PDF is acceptable in most instances).

Files within the secure partition and TDR will be reviewed regularly for obsolescence threat. If a file is considered to be in danger of obsolescence, appropriate measures will be taken to ensure that the file remains in an accessible state.

A surrogate copy for public access will be made in an appropriate format will be when necessary for files in the secure partition. Once ingested to the TDR, access copies of ingested files will be available for public use through the London Metropolitan Archives Collections Catalogue or on site at LMA where appropriate.

Standards and guidance which inform digital preservation strategies and processes developed by LMA will include the following:

  • The Dublin Core Metadata Element Set (ISO Standard 15836)
  • BS 4783 Storage, Transportation and Maintenance of Media for Use in Data Processing and Information Storage
  • Information and documentation - Records management (ISO Standard 15489:2001)
  • Space Data and Information Transfer Systems - Producer-Archive Interface - Methodology Abstract Standard (ISO standard ISO 20652)
  • The Open Archival Information System (OAIS)
  • Code of Practice for Legal Admissibility and Evidential Weight of Information Stored Electronically
  • PREMIS (PREservation Metadata: Implementation Strategies)
  • METS (Metadata Encoding and Transmission Standard)

The following organisations are relevant to digital preservation and will be consulted in the process of developing digital preservation strategies:

  • The Digital Preservation Coalition
  • The Digital Curation Centre
  • The National Archives
  • The Open Archives Initiative

The Head of Digital Services reporting to the Assistant Director will have overall responsibility for the secure partition and Trusted Digital Repository.

Acquisitions staff will provide advice to depositors (both City of London and external depositors).


Please complete a comment form or contact us if you wish to give feedback on this policy.

This policy will be reviewed at least every two years to make sure it remains timely and relevant.