# Maintenance Frequency Best Practices

This FGDC conformance check verifies the existence of a Maintenance Frequency Code in an ISO 19115 or 19115-3 metadata record. From the [FGDC guidance](https://www.fgdc.gov/technical-guidance/metadata/fgdc-technical-guidance-datagov-geoplatform-ngda.pdf):

***MD_MaintenanceFrequencyCode** is the frequency with which modifications and deletions are made to the data after it is first produced.*

*Metadata creators should include one of the several [Maintenance Frequency Codes](https://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml) within this element: **MD_MaintenanceFrequencyCode***

If frequency code is set to asNeeded or notPlanned, then the *status>MD\_ProgressCode* element should use the value 'completed'. 

## Best Practices

- If more than one Maintenance Frequency Code is specified, the value with the greatest range will be used. Example, annually takes precedent over weekly .
  - asNeeded or notPlanned codes will also need a Status Progress Codes of completed .

## ISO 19115

**Update Frequency Code**: *//gmd:MD_MaintenanceFrequencyCode/text()*

**Completed Status**: *//gmd:status/gmd:MD_ProgressCode/text()*

**Download URLs**: *//gmd:transferOptions/gmd:MD_DigitalTransferOptions/gmd:onLine/gmd:CI_OnlineResource/gmd:linkage/gmd:URL/text()*

## ISO 19115-3

**Update Frequency Code**: *//mmi:MD_MaintenanceFrequencyCode/text()*

**Completed Status**: *//mcc:MD_ProgressCode/text()*

**Download URLs**: *//mrd:transferOptions/mrd:MD_DigitalTransferOptions/mrd:onLine/cit:CI_OnlineResource/cit:linkage/gco:CharacterString/text()*

## More Information

- [MD_MaintenanceInformation](https://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml)
- [MD_MaintenanceFrequencyCode codelist definition](https://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml)