MARC record structure

[cKlee]

I'm just wondering. Why is an offset of 5 here. Does '_' indicate an empty subfield?

[phochste]

This is to provide backwards compatibility. In the past every due to bug non-controll fields also contained an underscore field:

[ '245' , ' ' , ' ' , '_' , '' , 'a' , 'test ]

vs:

[ '245' , ' ' , ' ' , 'a' , 'test ]

With these lines both will lead to the same result. The '_' subfield is ignored for non-controll fields

[cKlee]

Thanks!