Identification of Original and Reconstructed Web Resources

1. Purpose

This Technical Note establishes the Bureau of Digital Antiquities’ procedure for distinguishing surviving original web resources from archival representations, mirrors, restored copies, reconstructions and modern recreations.

Visual similarity alone is insufficient to establish the identity or provenance of a Digital Object.

A resource may reproduce the appearance and content of an historical website with considerable accuracy while existing within a substantially different technical, administrative or documentary context.

Conversely, an original resource may have undergone technical changes while retaining sufficient continuity to remain the same Digital Object.

The purpose of examination is therefore to establish what kind of resource is being observed and the evidential basis for that determination.

2. Scope

This procedure may be applied where:

• an historical website remains publicly accessible;
• a resource claims to preserve or reproduce an earlier website;
• an archival system provides access to captured web material;
• multiple versions of an historical resource exist;
• a mirror or restored copy may be mistaken for the original;
• an original resource has undergone substantial technical modification;
• a current resource reproduces an earlier visual design;
• the provenance of a surviving copy is uncertain; or
• the Bureau must determine how a resource should be represented in a Digital Object Record or publication.

The procedure concerns identification and provenance.

It does not determine copyright ownership, legal authenticity or authority to operate a particular network resource.

3. Categories of Resource

For examination purposes, a web resource may be described using one or more of the following categories.

3.1 Original Resource

An Original Resource is a surviving instance of the Digital Object with documented or reasonably established continuity from its historical operation.

Original does not necessarily mean technically unchanged.

Server infrastructure, protocols, hosting arrangements, individual files and other implementation details may change while the Digital Object retains historical continuity.

3.2 Archival Representation

An Archival Representation is material preserved and presented through an archival system rather than through the original operational environment.

An archival representation may preserve substantial portions of a Digital Object but should not ordinarily be described as the live original resource.

3.3 Mirror

A Mirror is a copy of a resource made available at another network location while substantially reproducing material from another instance.

A mirror may be contemporary with the original or created later.

Its evidential value depends upon its provenance and relationship to the source material.

3.4 Restored Copy

A Restored Copy is a resource reconstructed from retained original material with the purpose of returning some or all of the Digital Object to an accessible state.

A restored copy may contain authentic original files while operating in a later technical environment.

3.5 Reconstruction

A Reconstruction is a later attempt to reproduce a Digital Object using surviving evidence, retained material, archival captures or other sources.

A reconstruction may be historically valuable and highly accurate without being the original resource.

3.6 Recreation

A Recreation is a later resource inspired by or intentionally reproducing the appearance, behaviour or concept of an historical Digital Object without claiming direct operational continuity.

The distinction between reconstruction and recreation may depend upon purpose, source material and documented provenance.

Where that distinction cannot be established, the uncertainty should be retained.

4. Examination Principle

Identification should be based upon multiple forms of evidence where available.

No single characteristic should ordinarily be treated as conclusive.

In particular:

• visual similarity does not establish originality;
• an historical domain does not establish continuity;
• original files do not necessarily establish an original operational instance;
• modern infrastructure does not necessarily establish reconstruction; and
• archival presentation does not establish complete preservation.

The examiner should determine which explanation is best supported by the available evidence while preserving material uncertainty.

5. Network Location

Network location may provide important provenance evidence.

The examiner should establish, where practicable:

1. the current address;
2. historically documented addresses;
3. whether redirection occurs;
4. whether the current location is historically associated with the object;
5. whether the domain or hostname has changed ownership or purpose; and
6. whether available evidence documents migration between locations.

Assessment of redirected or reassigned locations should follow TN-000002 — Assessment of Redirected and Reassigned Network Locations.

An original historical address strengthens a continuity assessment where other evidence is consistent with that interpretation, but address alone is not sufficient.

6. Content Continuity

The examiner should compare the observed resource with available historical evidence.

Relevant characteristics may include:

• page titles;
• text;
• images;
• navigation;
• filenames and paths;
• directory structure;
• downloadable material;
• internal and external hyperlinks;
• metadata;
• scripts;
• stylesheets; and
• other retained assets.

Exact correspondence is not required for continuity.

Historical websites frequently changed during their operational lives.

The examination should instead determine whether differences are consistent with ordinary development, maintenance or migration, or whether they indicate later reconstruction or replacement.

7. Technical Characteristics

Technical evidence may assist in determining the nature of a resource.

Relevant observations may include:

• document structure;
• markup conventions;
• file naming;
• asset organisation;
• script dependencies;
• image formats;
• server behaviour;
• HTTP response characteristics;
• redirects;
• generated metadata;
• embedded timestamps; and
• references to obsolete or contemporary technologies.

Technical characteristics should be interpreted cautiously.

Old markup may be deliberately reproduced by a modern reconstruction.

Likewise, an original website may be served by modern infrastructure while retaining historical content.

The age of an individual technology therefore does not establish the age of the resource being examined.

8. File and Metadata Evidence

Where files are available for examination, retained metadata may contribute to provenance assessment.

Potentially relevant evidence includes:

• modification timestamps;
• embedded creation information;
• software-generated metadata;
• filenames;
• directory relationships;
• comments within source files;
• version identifiers; and
• references to historical systems or paths.

Metadata should not be assumed to represent original creation information.

Copying, extraction, archival processing, migration and restoration may alter timestamps or other attributes.

Metadata should therefore be interpreted in relation to the known custody and technical history of the material.

9. Archival Comparison

Archival captures may provide reference points for comparison with a current resource.

The examiner may compare:

• visible content;
• page structure;
• paths;
• asset names;
• images;
• hyperlinks;
• textual changes; and
• observed dates of availability.

Agreement between a current resource and historical captures may support a continuity assessment.

It does not by itself establish that the current files are the same files observed historically.

Likewise, differences do not necessarily establish reconstruction where the original resource underwent documented changes.

Archival evidence should be treated in accordance with PM-000002 — Citation and Source Attribution Standard.

10. Archival Replay

A website accessed through an archival replay system should ordinarily be identified as an archival representation.

Replay systems may modify the presentation or behaviour of captured material in order to provide access.

Such modifications may include:

• rewritten hyperlinks;
• inserted navigation controls;
• altered resource addresses;
• substituted responses;
• unavailable external dependencies; and
• incomplete execution of historical scripts.

The resulting representation may remain valuable evidence of the historical resource.

It should not be described as direct observation of the original operational environment.

11. Mirrors

Where a mirror is encountered, the examiner should attempt to establish:

• the source from which it was copied;
• the date or approximate period of copying;
• the responsible person or organisation;
• whether the copy was authorised or contemporaneous;
• whether the mirrored material was subsequently modified; and
• whether the original source remains identifiable.

A mirror may preserve material lost from the original location.

This preservation value does not make the mirror the original Digital Object.

Where appropriate, the mirror may itself warrant separate documentation as a related Digital Object or preservation resource.

12. Restored Resources

A restored resource may occupy an intermediate position between an original operational resource and a reconstruction.

For example, surviving original files may be placed on new infrastructure after a period of unavailability.

Assessment should consider:

• whether the files originate from the historical resource;
• whether custody can be established;
• whether the responsible operator remains associated with the resource;
• the extent of technical modification;
• whether missing material has been recreated;
• whether the restoration is documented; and
• whether the resource is represented publicly as restored.

The Bureau should describe the condition accurately rather than forcing the resource into an unnecessarily absolute classification.

A resource may therefore be described as a restored instance of an original Digital Object where the evidence supports that formulation.

13. Reconstructions

Reconstructions should be assessed according to their evidential basis.

The examiner should consider:

• the sources used;
• whether original files were available;
• the extent of material recreated manually;
• reliance upon archival captures;
• documented departures from the historical resource;
• modern substitutions for unavailable dependencies; and
• the purpose for which the reconstruction was created.

A reconstruction may possess substantial preservation and research value.

Its value should not depend upon presenting it as an original resource.

Clear identification of reconstruction generally strengthens rather than diminishes its usefulness as documentary evidence.

14. Modern Recreations

A modern recreation may deliberately reproduce historical visual or technical characteristics.

Indicators may include:

• newly authored files;
• modern frameworks or dependencies;
• contemporary metadata;
• recreated rather than retained assets;
• explicit statements of recreation;
• historically inaccurate functionality; or
• presentation based primarily upon the appearance of an earlier resource.

None of these indicators should be applied mechanically.

A recreation may intentionally use historically accurate technology, while an original resource may have been modernised.

The determination should be based upon provenance and continuity rather than aesthetic appearance.

15. Claims of Originality

Statements made by the operator of a resource may provide useful evidence but should not automatically determine the Bureau’s assessment.

Claims such as:

• “original website”;
• “restored”;
• “official archive”;
• “mirror”;
• “preserved version”; or
• “reconstruction”

should be documented where relevant and assessed alongside other available evidence.

Where the Bureau has not independently established the claim, the publication or Digital Object Record should distinguish the operator’s description from the Bureau’s determination.

16. Conflicting Evidence

Evidence concerning the origin of a resource may conflict.

For example:

• a domain may be historically correct while files appear to have been reconstructed;
• original files may be hosted at a later unrelated domain;
• an operator may describe a resource as original while archival evidence indicates substantial replacement;
• metadata may conflict with documented custody; or
• different surviving copies may each preserve material absent from the others.

Conflicting evidence should not be silently resolved for the sake of a simple classification.

Where necessary, the resource should remain provisionally or partially classified until further evidence becomes available.

17. Assessment Outcomes

Following examination, the Bureau may describe a resource using an appropriate finding, including:

Original — Continuous — available evidence supports continuity with the historically operational Digital Object.

Original — Modified — continuity is supported, but the resource has undergone material technical or content changes.

Original — Restored — continuity with the Digital Object is supported, but public accessibility has been re-established through restoration.

Archival Representation — the resource is being presented through an archival system based upon historical captures.

Mirror — the resource is a copy maintained separately from the original instance.

Reconstruction — the resource has been reassembled or reproduced from historical material or evidence without sufficient operational continuity to be treated as the original instance.

Recreation — the resource is a later reproduction or reinterpretation without established direct continuity.

Unresolved — the available evidence is insufficient or contradictory.

These findings may be supplemented with explanatory notes where the condition cannot be represented adequately by a single term.

18. Catalogue Treatment

A Digital Object Record should identify the nature of the resource through which the object is presently represented where that distinction is material.

The catalogue should avoid:

• presenting an archival replay URL as the original historical address;
• identifying a mirror as the original instance without supporting evidence;
• presenting a reconstruction as continuous merely because it reproduces the historical appearance;
• treating modern infrastructure as proof that a resource is reconstructed; or
• removing historically significant addresses solely because they no longer provide current access.

Where multiple representations survive, their relationships should be documented where practicable.

19. Referral for Forensic Examination

Further forensic examination may be appropriate where:

• provenance is materially disputed;
• a resource may contain surviving original files of uncertain custody;
• multiple copies claim originality;
• metadata requires technical interpretation;
• reconstruction has been performed without adequate documentation;
• a significant catalogue determination depends upon technical evidence; or
• the distinction between original and reconstructed material materially affects a Field Report or preservation assessment.

The examination should be proportionate to the significance of the determination.

Not every Digital Object requires exhaustive forensic analysis.

20. Relationship to Existing Procedure

This Technical Note should be read together with:

• TN-000001 — Verification of Publicly Accessible Legacy Websites;
• TN-000002 — Assessment of Redirected and Reassigned Network Locations; and
• PM-000002 — Citation and Source Attribution Standard.

TN-000001 addresses verification of publicly accessible legacy websites.

TN-000002 addresses continuity between Digital Objects and changing network locations.

This Technical Note addresses the identity and provenance of the resource itself.

Together, these procedures provide a basis for distinguishing accessibility, location and object identity as separate but related questions in Bureau examination.

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Prepared by Clive R. Stollard
Chief Digital Forensics Officer
Digital Forensics Unit
Bureau of Digital Antiquities
1 October 2026