Several elements at the beginning of a metadata record (before gmd:identificationInfo) are describing the metadata record itself.

Guidances by elements

fileIdentifier

Each metadata record in the WIS is identified by a field called the fileIdentifier. If a metadata record is uploaded to the WIS metadata catalogue and has the same fileIdentifier as an existing record, the original is replaced provided the new record has a later date and time stamp.

It is, therefore, important that fileIdentifiers are chosen carefully. The regulations require only that the fileIdentifiers are unique. The standard approach is to use a fileIdentifier of the form:

urn:x-wmo:md:<backwards_domain_name>:<identifier_assigned_by_organization_to_be_unique>

where the meanings of the terms in angle brackets are

<backwards_domain_name>

the domain name of the organization responsible for the metadata record, written in the opposite order from the order in a URL - the organization may choose to add a "sub-domain" to make it easier to ensure the uniqueness of identifiers assigned by different organizational units (e.g. int.eumetsat)

<identifier_assigned_by_organization_to_be_unique>

is a sequence of lettters, numbers and separator characters that is chosen to be unique within the organization (e.g. an internal identifier used by the organization for the product being described).

An example is:
urn:x-wmo:md:int.eumetsat::EO:EUM:DAT:MULT:RFEDIFFAVGPN

This can be entered into the metadata editor provided by a GISC, but if it is necessary to edit the xml, the relevant xml for the above example is:

<gmd:fileIdentifier xmlns:gml="http://www.opengis.net/gml">
   <gco:CharacerString>urn:x-wmo:int.wmo.lib:wmo306vI.1</gco:CharacterString>
</gmd:fileIdentifier>

WIS applies specific rules for the structure of fileIdentifiers associated with information that is exchanged globally using the Global Telecommunications System component of the WIS.

put the GTS limitations here.

language

characterSet

parentIdentifier

hierarchyLevel

hierarchyLevelName

contact

dateStamp

metadataStandardName

metadataStandardVersion

datasetURI

Example