An Atom ⟨link⟩ element (RFC 4287 §4.2.7) inside a syndication entry. The core Atom attributes carry the artefact URL and media type; the extension namespaces add file-level integrity and validation metadata.

Integrity

A consumer MUST be able to verify a downloaded artefact's integrity. At least one of md5Hash or sha256Hash SHOULD be present on every link whose rel is alternate or related. Where both are present, sha256Hash is authoritative.

The hash is computed over the byte stream that href resolves to, exactly as published — without any decompression or content-encoding negotiation.

Length

length is the byte count of that same stream. When present, it MUST match what the href resolves to.

Link relation. alternate denotes the primary artefact; related denotes ancillary content (release notes, licence).

Media type of the linked artefact (e.g. application/zip, application/pdf, application/json, application/fhir+json).

artefact download URL

Artefact size in bytes. When present, MUST match the href resolution exactly.

sct:md5Hash. Lowercase-hex MD5 of the artefact byte stream. 32 hex characters.

ncts:sha256Hash. Lowercase-hex SHA-256 of the artefact byte stream. 64 hex characters. When both md5Hash and sha256Hash are present, sha256Hash is authoritative.

onto:validated. Asserts that the publisher has re-verified the artefact at href against length and any hash since it was last published. Absence is equivalent to false.

An Atom ⟨link⟩ element (RFC 4287 §4.2.7) inside a syndication entry. The core Atom attributes carry the artefact URL and media type; the extension namespaces add file-level integrity and validation metadata.

Integrity

A consumer MUST be able to verify a downloaded artefact's integrity. At least one of md5Hash or sha256Hash SHOULD be present on every link whose rel is alternate or related. Where both are present, sha256Hash is authoritative.

The hash is computed over the byte stream that href resolves to, exactly as published — without any decompression or content-encoding negotiation.

Length

length is the byte count of that same stream. When present, it MUST match what the href resolves to.

Link relation. alternate denotes the primary artefact; related denotes ancillary content (release notes, licence).

Media type of the linked artefact (e.g. application/zip, application/pdf, application/json, application/fhir+json).

artefact download URL

Artefact size in bytes. When present, MUST match the href resolution exactly.

sct:md5Hash. Lowercase-hex MD5 of the artefact byte stream. 32 hex characters.

ncts:sha256Hash. Lowercase-hex SHA-256 of the artefact byte stream. 64 hex characters. When both md5Hash and sha256Hash are present, sha256Hash is authoritative.

onto:validated. Asserts that the publisher has re-verified the artefact at href against length and any hash since it was last published. Absence is equivalent to false.

An Atom ⟨link⟩ element (RFC 4287 §4.2.7) inside a syndication entry. The core Atom attributes carry the artefact URL and media type; the extension namespaces add file-level integrity and validation metadata.

Integrity

A consumer MUST be able to verify a downloaded artefact's integrity. At least one of md5Hash or sha256Hash SHOULD be present on every link whose rel is alternate or related. Where both are present, sha256Hash is authoritative.

The hash is computed over the byte stream that href resolves to, exactly as published — without any decompression or content-encoding negotiation.

Length

length is the byte count of that same stream. When present, it MUST match what the href resolves to.

Link relation. alternate denotes the primary artefact; related denotes ancillary content (release notes, licence).

Media type of the linked artefact (e.g. application/zip, application/pdf, application/json, application/fhir+json).

artefact download URL

Artefact size in bytes. When present, MUST match the href resolution exactly.

sct:md5Hash. Lowercase-hex MD5 of the artefact byte stream. 32 hex characters.

ncts:sha256Hash. Lowercase-hex SHA-256 of the artefact byte stream. 64 hex characters. When both md5Hash and sha256Hash are present, sha256Hash is authoritative.

onto:validated. Asserts that the publisher has re-verified the artefact at href against length and any hash since it was last published. Absence is equivalent to false.