The following Dublin Core fields are available in Omeka, together with some suggestions on interpreting the fields. The fields are vague by design so please consult with the DCMI element descriptions to be sure you are fulfilling the demands of your project. You may also want to review the detailed breakdown of item types with examples and a list of their item type metadata elements.
Read one example of Dublin Core interpretations from the North Carolina Exploring Culture and Heritage Online project.
Title
A name given to the resource.
Examples: title of a painting, photo, document; the name of a person when using the "person" item type; the name of a lesson plan
Subject
The topic of the resource.
Typically, the topic will be represented using keywords, key phrases, or classification codes. Recommended best practice is to use a controlled vocabulary. To describe the spatial or temporal topic of the resource, use the Coverage element. Examples: Library of Congress subject headings; subject-specific nomenclature.
Description
An account of the resource.
Description may include but is not limited to: an abstract, a table of contents, a graphical representation, or a free-text account of the resource.
Creator
An entity primarily responsible for making the resource.
Examples: author; artist; photographer; institutional author or producer, such as university or federal agency
Source
The resource from which the described resource is derived.
The described resource may be derived from the related resource in whole or in part. Recommended best practice is to identify the related resource by means of a string conforming to a formal identification system.
For some examples se the Identifier field.
Publisher
An entity responsible for making the resource available.
Examples: actual publisher, if there is one; entity or consortium publishing digital materials
Date
A point or period of time associated with an event in the lifecycle of the resource.
Date may be used to express temporal information at any level of granularity. Recommended best practice is to use an encoding scheme, such as the W3CDTF profile of ISO 8601.
Date can be one of the trickiest fields to fill. You will want to decide how best to use it for your project for consistency. Where possible, a structured date such as YYYY-MM-DD for a specific day or YYYY for a specific year is preferred, but other formats or levels of specificity can be used (such as "circa 1940").
Contributor
An entity responsible for making contributions to the resource.
Entries here should be akin to the Creator field, but for entities that made a less significant or unknown contribution.
Rights
Information about rights held in and over the resource.
Typically, rights information includes a statement about various property rights associated with the resource, including intellectual property rights.
Examples: spell out conditions of use for specific items here; Creative Commons or other specific license; Public Domain.
Relation
A related resource.
Recommended best practice is to identify the related resource by means of a string conforming to a formal identification system.
Examples: a still image of a person entered as a "person" type.
Format
The file format, physical medium, or dimensions of a resource.
Examples: the Internet media type of a digital file; the physical size of an object; the duration of a film or audio clip; or the medium of a work of art
Language
A language of the resource.
BCP 47 language tags are the suggested standard.
Type
The nature or genre of the resource.
Recommended best practice is to use a controlled vocabulary such as the DCMI Type Vocabulary. To describe the file format, physical medium, or dimensions of the resource, use the Format element.
Identifier
An unambiguous reference to the resource within a given context.
Recommended best practice is to identify the resource by means of a string conforming to a formal identification system.
Examples: a URL, an ISBN, a catalog number
Coverage
The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant.
Spatial topic and spatial applicability may be a named place or a location specified by its geographic coordinates. Temporal topic may be a named period, date, or date range. A jurisdiction may be a named administrative entity or a geographic place to which the resource applies.
Recommended best practice is to use a controlled vocabulary such as the Thesaurus of Geographic Names (TGN). Where appropriate, named places or time periods can be used in preference to numeric identifiers such as sets of coordinates or date ranges.
The above material is from "Working with Dublin Core" in the Omeka S User Manual.