# The Header and Data Sections

Here we describe the contents of the main header sections (except from the storage declarations in the CLASS program itself). Note that, in the data file, the actual length of some of the sections is variable, e.g. the length of the switching information section depends on the number of different phases in the switching procedure.

Subsections

- General Parameters
- Position information
- Spectroscopic information (for spectra)
- Baseline information (for spectra or drifts)
- Scan numbers of initial observations
- Default plotting limits
- Switching information (for spectra)
- Calibration parameters
- For Skydips observations. No associated data.
- Gauss fit results (for spectra or drifts)
- "Stellar shell" profile fit results (for spectra)
- Hyperfine structure profile fit results (for spectra)
- Hyperfine structure absorption profile fit results (for spectra)
- Continuum drift description (for drifts)
- Beam-switching parameters (for spectra or drifts)
- Double gaussian and baseline fit results (for drifts)
- Herschel Space Observatory (HIFI)
- Comment Section
- Data Section