used a power law to describe the underlying continuum and a Gaussian profile to describe the emission-line region. Since the blue half of the emission line may be attenuated by absorption, a half-Gaussian was fitted to the red half of the emission line and the half-Gaussian was replicated to the blue half of the emission line. Both algorithms then computed the standard balnicity index ([Weymann]{} [et al.]{} 1991) of absorption to classify objects as HiBALs or as objects without detectable BAL troughs — nonBALs. The EDR spectra were also inspected by eye (by P. B. H.) and were classified as nonBALs, HiBALs, LoBALs, or FeLoBALs. Further details regarding the construction of the sample can be found in the catalog paper, (2003).

BALQSO Composite Construction and Fitting \[sec:composite\]
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BALQSO Composite Spectra
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\(2003) created geometric mean composite spectra of the classes of BALQSOs. The 185 complete-sample BALQSOs and 39 supplementary BALQSOs were partitioned into a HiBAL class (180 objects with high-ionization broad absorption troughs, such as , but without low-ionization broad absorption lines, such as ), a LoBAL class (34 objects with high- and low-ionization broad absorption lines), a combined class of both HiBALs and LoBALs, and the small class 