Metadata is any information that describes an item. In ArcGIS Online, an item's information is created, edited, and viewed on the item page. Some examples of item information include the item title, type, description, source, author, last modified date, thumbnail, and tags. This information helps others discover and validate the usefulness of the items. In ArcGIS, item information is saved with the item it describes. It is copied, moved, and deleted with the item.
Metadata can also take the form of standards-based metadata documents or records, which are commonly referred to as geospatial metadata or metadata. Providing standards-based metadata with your item helps people learn about the item and decide which item best meets their needs. In ArcGIS, the metadata is saved with the item it describes. It is copied, moved, and deleted with the item and appears with items as they are used throughout the system. For example, if your organization has enabled Open Data, metadata documents managed from ArcGIS Online are available in ArcGIS Hub sites from dataset pages, and the documents are included in shapefile downloads. The availability of standards-based metadata for these datasets helps ensure that your content is findable, accessible, interoperable, and reusable (FAIR).
Organizations can enable editing metadata, which allows members of the organization to use a built-in metadata editor to include additional standards-based metadata for all item types. Metadata can be included for all items in a portal including web maps, web scenes, and web apps. Organizations select a metadata style, which applies a style sheet for the metadata standard and the schema used to validate metadata according to the standard. The style also configures the organization’s experience for editing and viewing metadata according to the standard.
In addition to determining the information available for viewing and editing, the metadata style identifies the metadata standard you are following and the schema used to validate an item's metadata for the standard. Regardless of the applied style, the metadata is always stored in ArcGIS metadata format. This means that metadata is not lost if the organization switches the metadata style.
You can access the metadata of an item from the item's page. See View metadata for more information.
ArcGIS metadata storage format
Regardless of the applied style, ArcGIS Online stores the metadata in ArcGIS metadata storage format. Item owners use the built-in metadata editor on the item to include additional metadata. The ArcGIS metadata storage format contains all the elements that can have values in all metadata standards supported by ArcGIS. The ArcGIS format also stores item information, such as thumbnails, that is not included in the standards-based metadata styles. Metadata stored in the ArcGIS storage format can be transformed to a different standard by applying a different style. This means that metadata is not lost if the organization switches the metadata style.
Metadata styles, standards, and profiles
A metadata style configures the editing and viewing experience of the metadata content. A metadata style is like applying a style sheet to the ArcGIS metadata. The style controls how you view the metadata and the pages that appear in the metadata editor. A standards-based metadata style is designed to support a metadata standard or profile. The style determines how metadata is validated for that standard or profile.
The default item page allows you to see and edit a simple set of metadata elements for an item. The information is indexed and searchable and is available to be used by applications across the platform. The item information is straightforward and effective, suitable for anyone who doesn't need to adhere to specific metadata standards. When metadata is enabled for your organization, item information is synchronized with the item’s standards-based metadata.
Metadata styles
The following metadata styles are provided to support different metadata:
- Dublin Core+—This style allows you to view and edit metadata following the Dublin Core Metadata Initiative (DCMI) and validate it using the RDF and XML schemas that are available on the DCMI web site. This style is used for the default ArcGIS metadata style.
- FGDC CSDGM Metadata—This style allows you to view and edit metadata following the FGDC Content Standard for Digital Geospatial Metadata (CSDGM) guidelines and validate it using the CSDGM XML DTD.
- INSPIRE Metadata Directive—This style allows you to view and edit a complete ISO 19139 metadata document that adheres to the INSPIRE implementing rules and validate it using the ISO 19139 XML schemas.
- ISO 19139 Metadata Implementation Specification—This style allows you to view and edit a complete metadata document that complies with ISO standard 19139, Geographic information—Metadata—XML schema implementation, and validate it using the standard's XML schemas. Use this style to create metadata that complies with ISO standard 19115, Geographic information—Metadata.
- ISO 19139 Metadata Implementation Specification GML3.2—This style is identical to the one above, except the files use the GML 3.2 namespace, and therefore can be validated with versions of the ISO 19139 XML schemas that reference the GML 3.2 namespace. For example, use this style if you plan to validate the metadata files using the NOAA NCDDC XML schemas.
- North America Profile of ISO 19115 2003—This style allows you to view and edit a complete metadata document that complies with North American Profile of ISO 19115:2003—Geographic information—Metadata, and validate it using the ISO 19139 XML schemas.
- ISO 19115-3 XML Schema Implementation—This style allows you to view and edit a complete metadata document that complies with ISO content standard 19115-1, Geographic information—Metadata—Part 1: Fundamentals, and validate it using the standard's XML schemas defined as part of ISO 19115-3, Geographic information—Metadata—Part 3: XML schema implementation for fundamental concepts.
Share and transform the metadata style and encoding format
Sometimes you need to share a standards-based metadata document outside ArcGIS. Two common ways to share metadata are through a website URL and as a file.
Tip:
Optionally, you can obtain the metadata style information by printing or saving the web page content if the web browser provides those options.
To share the metadata website URL, display the metadata, and copy the URL from the address bar of the web browser.
Note:
The item must be shared publicly to be viewed by those who are not members of your organization.
In ArcGIS, the metadata is displayed using a well-known URL structure. The structure varies for item-level metadata and layer-level metadata available for hosted feature layers and hosted tables.
URL format for item-level metadata
The URL for item-level metadata includes the item ID and a format parameter to define what metadata style is applied. You can also alter the URL to define the encoding format.
In the following example URL, the item ID is a123b04cdef5, the ISO 19139 Metadata Implementation Specification format is applied, and the encoding is HTML:
https://www.arcgis.com/sharing/rest/content/items/a123b04cdef5/info/metadata/metadata.xml?format=iso19139&output=html
To change the encoding format for the page for the same item to XML, drop the output parameter, as shown below:
https://www.arcgis.com/sharing/rest/content/items/a123b04cdef5/info/metadata/metadata.xml?format=iso19139
URL format for layer-level metadata
The metadata URL for a layer in a hosted feature layer or hosted table includes the FeatureServer and the layer ID, and the parameter to change the encoding format differs from that used to change encoding for item-level metadata.
In the following example URL, the item ID is z987y06xwvu5, the layer ID is 0, the default format is applied, and the encoding format is in HTML:
https://www.arcgis.com/sharing/rest/content/items/z987y06xwvu5/info/FeatureServer/0/metadata/metadata.xml?format=default&output=html
To change the encoding format to XML for the same item and layer, use the f parameter as shown below:
https://www.arcgis.com/sharing/rest/content/items/z987y06xwvu5/info/FeatureServer/0/metadata/metadata.xml?format=default&f=xml
Format values
By default, metadata is displayed using the current default style applied by the item owner’s organization. To change the style displayed using the metadata document website URL, modify the value for the format parameter in the metadata URL. In the examples above, replace default with the desired style. Use the appropriate short name value shown in the table below.
Note:
Because each style requires different elements, changing the format parameter to a different value may result in the metadata document missing some element values required for the metadata style to be considered complete.
| Metadata style | Short name |
|---|---|
The current default style applied by the item owner's organization | default |
Dublin Core+ | dcplus |
ISO 19139 Metadata Implementation Specification | iso19139 |
ISO 19115-3 XML Schema Implementation | iso19115-3 |
INSPIRE Metadata Directive | INSPIRE |
North America Profile of ISO 19115 2003 | NAP |
FGDC CSDGM Metadata | fgdc |
Metadata standards and profiles
A metadata standard is a document identifying content that should be provided to describe geospatial resources such as maps, map services, vector data, imagery, and nonspatial resources such as tables and tools that are relevant to your spatial work. A metadata standard may also specify an XML schema describing the format in which the content should be conveyed. Typically, a standard XML format is defined using XML schema or document type definition (DTD). Standards are typically ratified by national or international standards bodies.
Many geospatial metadata standards are produced by ISO committees including ISO 19115 Geographic Information—Metadata and ISO 19119 Geographic Information—Metadata—Services, which are content standards. In contrast, ISO 19139 Geographic Information—Metadata—Implementation Specification provides a set of XML schemas that define the XML format in which ISO 19115 and ISO 19119 metadata content should be stored.
The Federal Geographic Data Committee (FGDC) created the Content Standard for Digital Geospatial Metadata (CSDGM) that has been used in the United States for many years; it is commonly referred to as the FGDC metadata standard. It is another example of a content standard. While there is an accepted format in which to store this content in XML format, there are also several other file formats that are commonly used to present the information.
A metadata profile is a document that modifies a metadata standard. A profile may reduce the overall number of metadata elements defined by a standard. A profile may further restrict whether a metadata element is optional, making it mandatory where before it was optional; however, a profile cannot make mandatory elements optional. A profile may further restrict the values allowed in a metadata element. Metadata profiles can be adopted by a standards body, agency, or organization in place of a metadata standard. One example of a metadata profile is the North America Profile of ISO 19115:2003 that has been jointly created and adopted by the United States and Canada.
Whether by choice or by obligation, if you plan to create metadata that follows a standard or profile, you can obtain a copy of the standard or profile document. For ISO standards, you must purchase the document from ISO or the national organization that participates in ISO, such as ANSI, in the United States. Profiles should be available from the organizations that create them.
Metadata considerations
Consider the following when using metadata:
- Currently, organizations can set only one metadata style.
- ArcGIS metadata format is the only format supported for importing metadata.
- Currently, the title element is not synchronized between the metadata editor and item page. This includes when you upload a metadata .xml file. The first time you open the editor, the element has the title from the item page. Any changes you make (and save) to the title in the metadata editor are saved to the standards-based metadata. They are not saved to the item page.
- Currently, edits you make to a hosted WFS layer's metadata do not update the capabilities file of the underlying WFS service.
- To view layer-level metadata for public layers with FGDC styling, your organization must allow anonymous access. If your organization is private—that is, if anonymous access is disabled—layer-level metadata for public layers is available by default with ISO styling.
- Edits to layer-level metadata are not synchronized with the item. Similarly, edits to item metadata are not synchronized with layer-level metadata.
- Answers to common questions about metadata in ArcGIS Online can be found in the Metadata section of FAQ.