As many slices as needed. In Type 1 format, the first word of each slice is an integer equal to the size of that slice. NUTS never used that value, it was included to make the format consistent with the Felix format from which it derived. To make things simpler, this spacer was eliminated in the Type 2 format. If the data is real only then every other word must be zero.
Subsequent slices follow immediately after the preceeding slice.
This offers much more flexibility for future additions to information stored in the header, because the exact location of any item in the header and the order of items is not fixed. Another advantage of this format is that the header can be viewed in any text editor. The data are organized as Real, Imag, Real, Imag, etc. An example is shown below, for a small 1 H spectrum.