  The spectrum of a supernova is a summation of numerous overlapping atomic
line signatures. Consequently, empirical measurements are limited in
application when compound features are assumed to be due to one or two spectral
lines. Here I address matters of spectroscopic boundaries between normal and
peculiar type I supernovae using multi-component empirical metrics. I discuss
some obstacles faced when using supernova spectra to pair model with data and I
demonstrate how spectrum synthesis can benefit from fairly complete
observational coverage in wavelength and time.
