ISO 15836:2009 Information and documentation – Dublin Core set of metadata elements  There are a variety of metadata standards that meet the needs of specific user communities. The first three profiles listed below primarily support discovery and access. They are increasingly complex to implement and specialize in specific areas. The latter, PREMIS, was developed specifically to support digital preservation activities. This standard standardizes the components and structures of data quality measures, helps producers select the right actions when reporting dataset metadata, and ensures that users have relevant and comparable metrics when selecting the right dataset for their needs. It is closely linked to ISO 19113, which establishes principles and components for quality reporting, and ISO 19115, where data quality measurements are reported. A standard is defined as an agreement between a supplier and a consumer that provides reference documents for government procurement and international trade. With respect to spatial metadata, the main objective of the standards is to facilitate the ability to describe, manage, query, exchange, transmit, share and integrate spatial data and information. Metadata is generally classified as mandatory and not mandatory, mandatory metadata focuses on metadata to locate records so that they can be available for discovery.
Metadata requirements may vary and certain types of metadata elements may be important depending on the use or application of relevant data and the standards adopted. The tokenURI function of your ERC721 or the URI function of your ERC1155 contract must return an HTTP or IPFS URL. When queried, this URL should return a JSON data blob with your token`s metadata. You can see an example of a simple Python server to provide metadata in the OpenSea creature repository here. You can tell OpenSea that an NFT`s metadata can no longer be modified by anyone (in other words, it is “frozen”) by issuing this event from the smart contract: Providing asset metadata allows applications like OpenSea to retrieve large amounts of data for digital assets and easily display it in the application. The digital assets of a particular smart contract are usually represented only by a unique identifier (e.g. the token_id in ERC721), so the metadata allows these assets additional properties such as name, description, and image. The international working group Preservation Metadata: Implementation Strategies (PREMIS) was established by OCLC and RLG in 2003 to define a core set of preservation metadata elements that can be widely applied across the preservation community and to explore a number of practical application issues. In 2005, the group published its final report, which included version 1 of the PRMETT Data Dictionary. The associated XML schema allows PREMIS compliant metadata to be expressed consistently in XML. PREMIS was quickly accepted into the community and maintained by the Library of Congress. He won the Digital Preservation Award from the Digital Preservation Coalition in 2005.
Here`s an example of metadata for one of the OpenSea creatures: The PREMIS data model builds on the Open Archival Information System (OAIS) reference model (ISO 14721) and defines the relationships between five digital preservation activities called entities: Intellectual Entities, Objects (divided into three types: representation, file, and bitstream), events, agents, and rights. For the description of the conservation activities of the last four entities, 108 sub-units and other qualifiers are defined. Only 8 of them are mandatory. The scope of the PREMIS Data Dictionary is limited to the digital preservation activities of maintaining viability, renderability, comprehensibility, authenticity and identity. It is assumed that metadata is generated automatically as much as possible. Implementers are expected to use other applicable metadata standards to describe mental entities, agent characteristics, access and/or distribution rights, media and material details, and the business rules of a repository. Best practices for metadata. DataONE.
www.dataone.org/best-practices/metadata If there is no appropriate metadata standard, you can create a readme file metadata document as described in this guide. If you use IPFS to host your metadata, your URL must be in ipfs:// format. For example, ipfs://QmTy8w65yBXgyfG2ZBg5TrfB2hPjrDQH3RCQFJGkARStJb. If you want to register on IPFS, we recommend Pinata for easy data storage. Here`s a tutorial from Chainlink to get you started: blog.chain.link/build-deploy-and-sell-your-own-dynamic-nft/. For more information about using decentralized metadata URIs, see IPFS and Arweave below. The UK government is committed to ensuring consistency in public sector information and improving access to public services. As part of this commitment, they developed e-GMS, a metadata standard for government information assets, to ensure consistency between government and public organizations.
Its use is mandatory in the sector and is part of the broader e-Government Interoperability (e-GIF) framework, which establishes guidelines and technical specifications to enable interoperability and easy access to information across the industry. The standard is currently in version 3 (2004), although version 3.1 will be released soon and a complete revision of version 4 is planned. The 15 elements of Dublin Core form the core of the standard and can easily be mapped to 5 other standards when interoperability between metadata sets from other disciplines is required. The other 10 elements take into account records management functions, data protection and access to information legislation, and basic retention information. A lightweight version of the standard, e-GMS for websites (currently version 3), is available for those who create metadata for websites. Metadata can include content such as contact information, geographic locations, details of units of measurement, abbreviations or codes used in the record, information about instruments and protocols, details of survey tools, provenance and version information, etc. In a lab environment, much of the content used to describe data is first collected in a notebook. If possible, structure your metadata with an appropriate and agreed standard metadata format. (See below for examples and guidelines.) To truly enable interoperability, metadata must be fully understood. Users need to understand what metadata needs to be created and what needs to be available to understand a resource. Metadata must be understandable by anyone who uses it. This is what makes standardized metadata so powerful and important.
The standards define exactly how geographic information and related services should be described by providing mandatory and conditional metadata sections, metadata entities, and metadata elements. This standard applies to data sets, independent datasets, individual geographic features, and feature properties. To this end, there are now many national spatial metadata standards, as well as international metadata standards, to promote global interoperability. Many stakeholders in the National Spatial Data Infrastructure (NGDI) have a long history of using the CSDGM and it will have a legacy for many years to come. However, the use of an international standard has its advantages when working collaboratively and the international spatial metadata standard ISO 19115 is created. The standard is part of the ISO Suite of Standards for Geographic Information (19100 series). ISO 19115 and its parts provide information on the identification, extent, quality, spatial and temporal aspects, content, spatial reference, presentation, distribution and other characteristics of digital geographic data and services. The following sections provide an overview of international metadata standards. This standard defines the schema required for the description of geographic information and services. The standard applies to all geographic resources: it applies to serial records, records, individual geographic features and their attributes. It also applies to geographic data services. The standard defines the minimum set of metadata required to perform basic metadata functions such as resource discovery, determining the usability of a resource, and accessing resources, as well as optional metadata elements to support a more comprehensive description that enables a wide range of metadata applications.
Many different metadata schemas are developed as standards in various disciplines such as librarianship, education, archiving, e-commerce, and art. The following table provides an overview of the available metadata standards. Metadata elements grouped into groups designed for a specific purpose, such as a specific domain or type of information resource, are called metadata schemas.