Codelists from the Metadata for Maintenance Information (mex) Namespace Codelists from the Metadata for Maintenance Information (mex) Namespace ISO TC211 Metadata Standards 1.1 2017-09-10 eng UTF-8 MD_MaintenanceFrequencyCode MD_MaintenanceFrequencyCode frequency with which modifications and deletions are made to the data after it is first produced frequency with which modifications and deletions are made to the data after it is first produced continual continual resource is repeatedly and frequently updated resource is repeatedly and frequently updated daily daily resource is updated each day resource is updated each day weekly weekly resource is updated on a weekly basis resource is updated on a weekly basis fortnightly fortnightly resource is updated every two weeks resource is updated every two weeks monthly monthly resource is updated each month resource is updated each month quarterly quarterly resource is updated every three months resource is updated every three months biannually biannually resource is updated twice each year resource is updated twice each year annually annually resource is updated every year resource is updated every year asNeeded asNeeded resource is updated as deemed necessary resource is updated as deemed necessary irregular irregular resource is updated in intervals that are uneven in duration resource is updated in intervals that are uneven in duration notPlanned notPlanned there are no plans to update the data there are no plans to update the data unknown unknown frequency of maintenance for the data is not known frequency of maintenance for the data is not known periodic periodic resource is updated at regular intervals resource is updated at regular intervals semimonthly semimonthly resource updated twice a monthly resource updated twice a monthly biennially biennially resource is updated every 2 years resource is updated every 2 years