Overview

The properties of the DataCite Metadata Schema are presented in this section.

Conventions

Levels of obligation

There are three different levels of obligation for the metadata properties:

• Mandatory (M) properties must be provided;

• Recommended (R) properties are optional, but strongly recommended for interoperability; and

• Optional (O) (but not specifically recommended) properties provide richer description.

Repositories who wish to enhance the prospects that their metadata will be found, cited, and linked to original research are strongly encouraged to submit both the Recommended and Mandatory sets of properties. Together, the Mandatory and Recommended sets of properties and their sub-properties are especially valuable to information seekers and added-service providers, such as indexers. The Metadata Working Group members strongly urge the inclusion of metadata identified as Recommended for the purpose of achieving greater exposure for the resource’s metadata record and, therefore, the underlying research itself.

The prospect that a resource’s metadata will be found, cited, and linked is enhanced by using the combined Mandatory and Recommended “super set” of properties and sub-properties. These are bolded in Table 1 (Mandatory Properties) and Table 2 (Recommended and Optional Properties).

Naming and numbering

Properties and sub-properties have naming and numbering conventions as follows:

• properties begin with a capital letter (e.g., Creator)

• sub-properties begin with a lower case letter, with subsequent words using capital letters (e.g., creatorName, nameType) 1

Each property is numbered. The major properties are numbered 1-20.

Occurrences

“Occurrences” indicates cardinality/quantity constraints for the properties as follows:

• 0-n = optional and repeatable

• 0-1 = optional, but not repeatable

• 1-n = required and repeatable

• 1 = required, but not repeatable

XML schema

In the XML schema:

• Properties are always represented as elements.

• Sub-properties can be either sub-elements or attributes.

The numbering convention distinguishes elements and sub-elements from attributes:

• Elements and sub-elements are numbered (e.g., 2. Creator, 2.1 creatorName).

• Attributes are represented with letters (e.g., 2.1.a nameType)

Because XML attributes are not repeatable, sub-properties represented as attributes will always have an occurrence of either 0-1 (optional) or 1 (required).

XML representation	Property or sub-property	Example
Element	Property	2. Creator
Sub-element	Sub-property	2.1 creatorName
Attribute	Sub-property	2.1.a nameType

XML provides an xml:lang attribute 2 that can be used on the following properties and sub-properties:

• 3. Title

• 4. Publisher

• 6. Subject

• 16. Rights

• 17. Description

• 20.3 title

• 2.1 creatorName when 2.1.a nameType is “Organizational”

• 7.1 contributorName when 7.1.a nameType is “Organizational”

This provides a way to describe the language used for the content of the specified properties.

The schema provides the 9. Language property to be used to describe the language of the resource.

Mandatory Properties

The mandatory properties must be supplied with any initial metadata submission to DataCite, together with their relevant sub-properties. If one of the required properties is unavailable, please use one of the standard (machine-recognizable) codes listed in Appendix 3: Standard values for unknown information.

Table 1: DataCite Mandatory Properties

ID	Property	Obligation
1	Identifier	M
2	Creator	M
3	Title	M
4	Publisher	M
5	PublicationYear	M
10	ResourceType	M

Recommended and Optional Properties

Of the Recommended set of properties, the most important to use is the Description property, together with the Recommended sub-property descriptionType="Abstract" (see 17. Description). Appendix 1 includes detailed descriptions of controlled list values, using bold text to indicate those values that are especially important for information seekers and added service providers. It cannot be emphasized enough how valuable an Abstract is to other scholars in finding the resource and then determining whether or not the resource, once found, is worth investigating further, re-using, or validating.

Table 2: DataCite Recommended and Optional Properties

ID	Property	Obligation
6	Subject	R
7	Contributor	R
8	Date	R
9	Language	O
11	AlternateIdentifier	O
12	RelatedIdentifier	R
13	Size	O
14	Format	O
15	Version	O
16	Rights	O
17	Description	R
18	GeoLocation	R
19	FundingReference	O
20	RelatedItem	O

Footnotes

1

This convention is known as “camelCase.” https://en.wikipedia.org/wiki/CamelCase

2

Allowed values IETF BCP 47, ISO 639-1 language codes, e.g. en, de, fr