For INAA data, precision was determined from eight replicate analyses of Standard BOB-1, except for Sc, for which six replicates were analyzed. Precisions, as estimated by standard deviations (in ppm), are: Sc = 1.4, La = 0.08, Ce = 0.32, Nd = 0.26, Sm = 0.10, Eu = 0.03, Tb = 0.07, Yb = 0.08, Lu = 0.01, Hf = 0.07, Ta = 0.01, and Th = 0.02. A measure of INAA accuracy is provided by recommended vs. our average measured values for BOB-1, and of ICPMS accuracy by the average of six recent analyses of W-2 vs. Jenner etal. 's [1990, doi:10.1016/0009-2541(90)90145-W] preferred values. The standard deviations of the W-2 analyses are (in ppm): Sc= 1.7, Y= 1.3, Zr = 4.5, Nb = 0.2, Cs = 0.08, Rb = 0.9, Ba = 7.0, La = 0.48, Ce = 0.76, Pr = 0.16, Nd = 0.59, Sm = 0.17, Eu = 0.05, Gd = 0.13, Tb = 0.05, Dy = 0.17, Ho = 0.05, Er = 0.07, Tm = 0.03, Yb = 0.06, Lu = 0.03, Hf = 0.13, Ta = 0.06, Th = 0.18, and U = 0.02.