(registered 2025-10-17, last updated 2025-10-17)

Scheme name: linkid

Status: Provisional

Applications/protocols that use this scheme name:
Link integrity and preservation systems for web and document content; resolver services and clients that
detect, analyze, and repair broken hyperlinks; archival and enterprise content platforms using persistent
identifiers.

Contact:
Christian Nyffenegger, Founder & CEO, Link Genetic GmbH
Email: c.n&linkgenetic.com
Address: Link Genetic GmbH, Leugrueb 21, 8126 Zumikon, Switzerland
Web: https://linkgenetic.com/

Change controller:
Link Genetic GmbH (on behalf of the LinkID specification maintainers)

References:
LinkID Specification v1.0 (public draft): https://github.com/Link-Genetic-GmbH/lid/
RFC 3986 (URI Generic Syntax)
RFC 7595 (URI Scheme Guidelines and Registration)

Scheme syntax (ABNF using RFC 3986 productions):
linkid-URI = "linkid:" linkid-id [ "?" query ] [ "#" fragment ] linkid-id = linkid-seg *( "/" linkid-seg ) linkid-seg =
1*( unreserved / pct-encoded / sub-delims / ":" ) ; unreserved / pct-encoded / sub-delims / query / fragment
per RFC 3986 Scheme name is case-insensitive; the linkid-id is case-sensitive unless specified by a given
namespace profile. Percent-encoding follows RFC 3986.

Scheme semantics:
linkid: identifies a persistent LinkID representing a target resource (e.g., a web page, document section,
dataset, media asset). A linkid: does not embed a direct network location; resolution to a current actionable
locator (e.g., https: URL) is performed by one or more LinkID resolvers per the LinkID Spec. The identifier
remains stable even when the resource moves or is renamed.

Encoding considerations:
linkid-id components are UTF-8 strings percent-encoded per RFC 3986 for any characters outside
unreserved. Producers SHOULD apply Unicode NFC before percent-encoding to improve comparison
stability.

Interoperability considerations:
- Conforms to RFC 3986 generic syntax.
- Namespace profiling allowed (e.g., linkid:ns:local-id/path).
- Comparison rules per RFC 3986; profiles MAY define canonicalization.

Security considerations:
- Phishing/misdirection: resolution maps identifiers to current locators; validate origin and use TLS.
- Normalization/comparison: follow RFC 3986; avoid lossy transformations.
- Authorization: access control is enforced by resolvers/targets.
- Integrity/abuse: use TLS, consider signed responses, rate limiting, and logging.

Privacy considerations:
- linkid: values SHOULD avoid embedding personal data.
- Resolution requests can reveal user interest; operators SHOULD minimize logs and apply retention
limits.

Examples:
linkid:doc:acme/handbook/2025/section-3 linkid:doi:10.1234/xyz-2025-07#methods
linkid:media:images/product-42?v=2 linkid:archive:ch.admin/finrep/2024/Q4

Intended usage: Common

Restrictions on usage: None beyond RFC 3986 and this registration.

Author/Change controller statement:
Link Genetic GmbH maintains the LinkID specification and welcomes multi-stakeholder governance as
adoption grows.

Public Repository Reference:
All current specification drafts, reference implementations, and interoperability documentation are publicly
available at:
https://github.com/Link-Genetic-GmbH/lid/