Descriptor/ Button 
Explanation 
ABL

Area: sum of intensities between two reference points with the baseline subtracted. 
ALV

Area: sum of all intensities between two reference points; the baseline is defined by the level of the reference point b_{1}. 
ARW

Area: the sum of intensities between two reference points; no baseline is subtracted. 
BBL

The logarithm of the ratio of two peak areas (with the baseline subtracted) weighted by the area of the second peak. 
BRW

The logarithm of the ratio of two peak areas weighted by the area of the second peak; no baseline is subtracted. 
CEN

Centroid: the position of the centroid of the spectral line within the boundaries b_{1} and b_{2}.

COO

Correlation with a positive triangle template peak within the boundaries b_{1} and b_{2}.

GC

Significant positive correlation (level of significance = 0.01) with a general Gaussian template peak.

GCI

Significant positive correlation (level of significance = 0.01) with an inverse general Gaussian template peak.

PBL

Peak: single intensity at a particular wavelength or mass; the baseline is subtracted. 
PLV

Peak: single intensity at a particular wavelength or mass; the baseline is defined by the level of a single reference point b_{1}. 
PRW

Raw peak: single unprocessed intensity at a particular wavelength or mass; the baseline is not subtracted. 
RBL

Peak ratio: the logarithm of the ratio of two peak intensities at two different wavelengths weighted by the intensity of the second peak.

RLV

Peak ratio: the logarithm of the ratio of two peak intensities at two different wavelengths weighted by the intensity of the second peak.

RRW

Raw peak ratio: the logarithm of the ratio of two peak intensities at two different wavelengths weighted by the intensity of the second peak. 
TC

Significant positive correlation (level of significance = 0.01) with a positive triangle template peak, multiplied by the signal area.

TCI

Significant positive correlation (level of significance = 0.01) with an negative triangle template peak, multiplied by the signal area. 
VAR

Variance of the first derivative of the spectral line within the boundaries b_{1} and b_{2}.
