Titles should be succinct yet descriptive including the topic, and where relevant, temporal info, geography and related programs in a way that distinguishes it from other, similar resources. To this end, EPA recommends the following template:

{Subject, Geographic Extent, Relevant Time Period, Data Owner/Provider, Office/Region/Research Lab of Data Owner}

Any individual component of this title template may be omitted if not applicable. For example, there is no need to include a date if data are frequently or continuously updated. Similarly, if the geographic extent is implicit in the subject, i.e. National Hydrography Dataset, it may be omitted provided that the actual extent of the data matches the extent implied in the title (an example of a dataset whose actual extent does not match the implicitly titled extent would be National Hydrography Dataset clipped to a given state). Geographic Extent should always refer to a place name, not a bounding box or coordinates. Spell out any acronyms.

This element is the date when the data resource was published or otherwise made available for release. Dates should be ISO 8601 of highest resolution. In other words, as much of YYYY-MM-DDThh:mm:ss.sTZD as is relevant to this dataset. If there is a need to reflect that the dataset is continually updated, non geospatial records can use ISO 8601 repeating intervals in this field. For instance, R/P1D for daily, R/P2W for every two weeks, and R/PT5M for every five minutes. Geospatial records should use
//gmd:identificationInfo/gmd:MD_DataIdentification/gmd:resourceMaintenance/
gmd:MD_MaintenanceInformation/gmd:maintenanceAndUpdateFrequency/
gmd:userDefinedMaintenanceFrequency/gts:TM_PeriodDuration
to document frequent maintenance intervals per the official guidance. 

• EPA Category: Mission Sensitive, NARA Category: Critical Infrastructure
• EPA Category: Drinking Water Vulnerability Assessments, NARA Category: Critical Infrastructure-Water Assessments
• EPA Category: Sensitive Drinking Water Related, NARA Category: Critical Infrastructure-Water Assessments
• EPA Category: IT Security, NARA Category: Information Systems Vulnerability Information
• EPA Category: Law Enforcement Sensitive, NARA Category: Law Enforcement
• EPA Category: Attorney Client Privilege, NARA Category: Legal-Privilege
• EPA Category: Attorney Work Product, NARA Category: Legal-Privilege
• EPA Category: Deliberative Process Privilege, NARA Category: Legal-Privilege
• EPA Category: Personally Identifiable Information (PII), NARA Category: Privacy
• EPA Category: Proprietary, NARA Category: Proprietary
• EPA Category: Confidential Business Information, NARA Category: Proprietary-Manufacturer
• EPA Category: Source Selection Information, NARA Category: Proprietary-Source Selection

ArcGIS Metadata XML:

<resConst>
    <LegConsts>
        <useLimit>EPA Public Domain License</useLimit>
        <accessConsts>
            <RestrictCd value="009">licenceUnrestricted</RestrictCd>
        </accessConsts>
        <othConsts>https://edg.epa.gov/EPA_Data_License.html</othConsts>
    </LegConsts>
</resConst>

ISO XML:

  <resourceConstraints>
    <MD_LegalConstraints>
      <useLimitation>
        <gco:CharacterString>EPA Public Domain License</gco:CharacterString>
      </useLimitation>
      <accessConstraints>
        <MD_RestrictionCode codeList="http://www.fgdc.gov/nap/metadata/register/codelists.html#napMD_RestrictionCode" codeListValue="licenseUnrestricted" codeSpace="ISOTC211/19139/NAP">licenseUnrestricted</MD_RestrictionCode>
      </accessConstraints>
      <otherConstraints>
        <gco:CharacterString>https://edg.epa.gov/EPA_Data_License.html</gco:CharacterString>
      </otherConstraints>
    </MD_LegalConstraints>
  </resourceConstraints>

At least one online linkage should be provided for all datasets - if no linkage of any kind is provided, EDG staff may ask for a justification. Every URL must contain an associated function code. Other associated elements such as Title and Description are optional but recommended. Data publishers are encouraged to publish datasets as both downloads and web services. Below is some additional guidance for specific online linkages:

• Download URL - Function Code: Download. URL providing direct access to the downloadable distribution of a dataset.
• Web Service - Function Code: webService. Endpoint of web service to access dataset. This is typically the REST endpoint for an ArcGIS Server service, but it may also be a WMS GetCapabilities URL or a SOAP WSDL endpoint.
• Data Dictionary - Function Code: information. URL for accessing related documents such as technical information about a dataset, developer documentation, etc.
• Homepage URL - Function Code: search. Alternative landing page used to redirect user to a contextual, Agency-hosted “homepage” for the Dataset or API when selecting this resource from a metadata catalog. This field is not intended for an agency’s homepage (e.g. www.agency.gov), but rather if a dataset has a human-friendly hub or landing page that users should be directed to for all resources tied to the dataset. This allows agencies to better specify what a visitor receives after selecting one of the agency’s datasets on Data.gov or in third-party mashups.

Online Resource 1 Linkage Download URL: "https://edg.epa.gov/data/Public/OEI/EPA_Facilities/EPA_Locations.zip" 

Online Resource 2 Linkage Map Service: "https://geodata.epa.gov/arcgis/rest/services/OEI/EPA_Locations/MapServer"