Blockchain Commons Known Values Registry: Compact Integer Identifiers for Ontological Concepts

*TL;DR:* I'm seeking CCG community input on a compact identifier registry
we've developed at Blockchain Commons. Our Known Values Registry
(BCR-2023-002) maps ontological concepts — predicates, classes, properties
— to 64-bit integers, providing a compact binary representation while
preserving semantic meaning.

We've already mapped several vocabularies this community uses (RDF, RDFS,
Dublin Core, FOAF, SKOS, Verifiable Credentials, Schema.org), and we're
developing new schemas for areas like principal authority, signature
context, and peer endorsements.

*Three questions for the community:*

- Are there other ontologies or vocabularies CCG uses that we should
prioritize mapping?

- Would schemas for principal authority (who directed vs who performed),
signature context (the capacity in which someone signs), and peer
endorsements be useful for VC implementations?

- Is anyone working on similar compact-identifier approaches?

Here's the detail on what we've built:

*The Known Values Registry*

BCR-2023-002 defines a namespace of 64-bit unsigned integers representing
ontological concepts — relationships, classes, properties, and enumerated
values. Each integer maps to a canonical name and equivalent URIs.


https://github.com/BlockchainCommons/Research/blob/master/papers/bcr-2023-002-known-value.md

We needed compact binary representation and deterministic encoding, but the
registry itself is independent of any particular encoding. While we
serialize these as CBOR (#6.40000) for use with Gordian Envelope, the
codepoint-to-concept mappings stand alone and can be used in any format or
protocol.

For example, rdf:type (codepoint 1) encodes as:

    CBOR diagnostic: 40000(1)
    Bytes: d9 9c 40 01  (4 bytes)

Compare that to the 47-byte URI "
http://www.w3.org/1999/02/22-rdf-syntax-ns#type". For documents with many
predicates, this adds up.

*What's Already Mapped*

We've assigned codepoints for several vocabularies this community uses:

- RDF (2000-2049): 21 entries
- RDFS (2050-2099): 15 entries
- OWL 2 (2100-2199): 75 entries
- Dublin Core Elements (2200-2299): 15 entries
- Dublin Core Terms (2300-2499): 89 entries
- FOAF (2500-2699): 75 entries
- SKOS (2700-2799): 32 entries
- Solid (2800-2899): 33 entries
- W3C Verifiable Credentials (2900-2999): 28 entries
- GS1 Web Vocabulary (3000-3999): 609 entries
- Schema.org (10000-19999): 2450 entries

These are 1:1 mappings — the Known Value codepoints reference the canonical
URIs from each ontology.

*Emerging Schemas*

We're also developing predicates for areas where we haven't found existing
schemas to leverage. These are currently in community review (see the
current PRs in the repository):

- Principal Authority — predicates for expressing who directed a work vs
who performed it (e.g., human holds principalAuthority over AI-generated
content)

- Signature Context — the capacity in which someone signs (e.g., CFO signs
onBehalfOf their corporation, not personally)

- Fair Witness — neutral third-party observation attestations (e.g., notary
attesting they observed a signature ceremony)

- Peer Endorsement — skill and collaboration endorsements distinct from
formal credentials (e.g., colleague endorsing another's security expertise
based on project work)

- CreativeWork Roles — contribution roles mapped to CRediT with ONIX, MARC
(e.g., distinguishing Author from Editor from Reviewer on a collaborative
work)

I'm planning to make these available as schemas useable with JSON-LD and
other formats at https://assertions.info for those working outside
CBOR/Envelope contexts, if the W3C CCG community finds them useful.

*Community Registry*

Codepoints 100,000+ are open for community registration via automated
GitHub workflow — submit a JSON file, validation runs, and upon merge you
have registered codepoints. No gatekeeping beyond schema conformance and
uniqueness checks.

*Resources*

Full registry with JSON exports:


https://github.com/BlockchainCommons/Research/tree/master/known-value-assignments

We also presented on Known Values at our January Gordian Community meeting:

Video:
    https://youtu.be/FiLNhx9BOuk?t=2658 (Known Value discussion starts at
44:18)

Transcript:

https://developer.blockchaincommons.com/meetings/2026-01-gordian/transcript/#known-values-discussion

-- Christopher Allen
   Blockchain Commons