MDG_DataMaint WIS » Documentation » Metadata Guidance » MDG_TechGuide » MDG_DataMaint Dataset Maintenance Several elements under MD_Metadata/identificationInfo describe how the resource will be maintained. 1. One-time resource 2. Periodically updated data 2.1. Hours of bulletin issuance 2.2. Cycle of publication 2.3. Metadata for terminated periodical data service