The IUE Ultraviolet Spectral Atlas and the first addendum were published by Wu et al. (1983, 1991) in printed and machine readable versions. This atlas and addendum contain UV spectra of 315 stars with spectral types ranging from O3 to M5 and many spectral type-luminosity class combinations. There were three criteria for selecting these stars: (1) they were not spectroscopic binaries or variables with significant changes in magnitude or color, (2) they must have well-determined spectral types (many rae MK standards) and (3) the stars should not be heavily reddened.
Further augmentation of the atlas is desirable to provide a more complete coverage of the spectral type-luminosity class combinations and more than one star per combination. The extra stars within a given combination guard against variability and peculiarity, and allow for a finite range of temperature, metallicity and gravity.
The previous atlas and addendum presented data that were obtained through the eleventh episode under IUE programs with C._C. Wu and D. Burstein as principal investigators. In this second addendum, we present the spectra obtained by Wu's programs during the twelfth through seventeenth episodes: SALCW, SAMCW, SANCW, SAOCW, SPACW and SAQCW that cover the period between July 1989 and September 1994. The data for 181 stars are included in this contribution. Most of these observations are high quality trails or pseudo-trails (multiple exposures in the large aperture).