Dublin Core schema

Built-in id: dcmi:elements:1.1

Published at: https://hawkeyexl.github.io/manni/schemas/dcmi/1.1.json

The fifteen elements of the Dublin Core Metadata Element Set, as published in the DCMI Recommendation of 2020-01-20. That date is worth noticing: this is a frozen specification, so unlike the toolchain pins, 1.1 will stay accurate indefinitely.

It is one of the metadata vocabularies. Dublin Core speaks to catalogues, repositories and library systems.

Use it

DCMI marks no element mandatory, so the schema requires nothing. Every element is repeatable in Dublin Core, so each accepts a single value or a list:

---
creator:
  - Ada Lovelace
  - Charles Babbage
date: 2026-08
---

Turning it on cannot fail a page for what it lacks, only for a value in the wrong shape:

manni.config.yaml

meta:
  schemas:
    - dcmi:elements:1.1

Fields

contributor, coverage, creator, date, description, format, identifier, language, publisher, relation, rights, source, subject, title, type.

Element	Type	Notes
date	string | array	W3CDTF, which permits reduced precision.
every other element	string | array	No format.

date is the one element with a format. It is encoded as W3CDTF, which permits reduced precision, so 2026, 2026-08, and 2026-08-23 are all valid. A full datetime carries a timezone. June 5th is not.

`type` is not enumerated, on purpose

DCMI publishes a Type Vocabulary (Collection, Dataset, Event, Image, InteractiveResource, MovingImage, PhysicalObject, Service, Software, Sound, StillImage, Text). It describes using that vocabulary as recommended best practice rather than requiring it. Enumerating it here would reject conforming documents that use a different controlled vocabulary. If your repo has standardised on the DCMI Type Vocabulary, write a one-property schema of your own. It $refs this built-in and narrows type.

Element names are unprefixed

This schema uses the bare term names the Recommendation defines, such as title, creator, and date. Documents that use the DCMI-HTML profile spelling in <meta name="DC.title"> carry a different set of keys and are not covered by this built-in.

Additional properties

Allowed. A page may carry keys beyond the fifteen elements.

Example

---
title: Release history
creator: Ada Lovelace
date: 2026-08-23
language: en
subject:
  - releases
  - changelog
---

A common mistake

A date written the way a person says it fails the W3CDTF pattern. The second line names the branch of the schema that raised it:

✗ docs/history.md
    /date  must match pattern "^[0-9]{4}(-[0-9]{2}(-[0-9]{2}(T[0-9]{2}:[0-9]{2}(:[0-9]{2}(\.[0-9]+)?)?(Z|[+-][0-9]{2}:[0-9]{2}))?)?)?$"  (line 3)  [dcmi:elements:1.1]
    /date  must match "else" schema  (line 3)  [dcmi:elements:1.1]