1. Introduction
2. Overview of the data reduction cascade
3. Pre-processing reductions
3.1. Pick-up noise elimination in bias frames
3.2. Intraorder background and pick-up noise modeling in science frames
4. Pipeline data reduction steps
4.1. Bias subtraction
4.2. Removal of cosmic ray hits
4.3. Wavelength calibration and order extraction
5. Post-pipeline reductions
5.1. Error map adjustments
5.2. Illumination background and pick-up noise subtraction
5.3. Bad pixel interpolation
5.4. Flat fielding
5.5. Illumination correction
5.6. Nodding
5.7. Sky subtraction for point-like objects
5.8. Optimal extraction of point-like objects
5.9. Absolute flux calibration and order merging
5.10. Fine-tuning of the wavelength calibration
6. Summary and conclusions