Demonstration of a measurement of a pseudo-equivalent width (pEW) for the Si IIλ6355 feature with Spextractor. The rest-frame spectrum with its uncertainty is shown in red. The vertical dashed black lines determine the wavelength boundaries of the feature. A dashed red line represents the pseudo-continuum connecting both sides of the spectral feature and the shaded blue area is the integral between the pseudo continuum and the binned spectrum within the defined wavelength boundaries, which defines the pEW.