Duration

MARC-Bib: 300a; 306a; 500a; 505a (Extent)

Check the 'Source' instruction to be sure that you are looking at the correct source(s) of information on the resource
If data on the resource and data as the element in the record are:
- PoR/PaE–check the Data Entry instructions:
  - data for this element must be Recorded as instructed: make sure the data is recorded as instructed
- PoR/AaE–check the Core instructions:
  - data for this element is LCCore:
    - if the data has been given as a wrong element, move it to the correct element
    - if you are following LC policy, add the data for this element
    - if you are not following LC policy, add the data if you feel it might be useful–remember the principles of differentiation and sufficiency
- AoR/PaE–check the Source instructions again:
  - since the Source for this element is or includes 'Any', accept the data, but only if it seems applicable
- AoR/AaE–go to the next element:
  - but be sure to check the resource carefully, if the data for the element is Core, or if the data is important for differentiating the resource from a similar resource
Check below, for any useful Notes