The use of uniformity of the quiet-zone (QZ) in determining the maximum size of test antenna that can be measured in a given point-source compact antenna test range (CATR) has been the accepted method since its inception [1]. Furthermore, the definition of a quiet zone (QZ) having amplitude taper of less than 1 dB, amplitude ripple of less than ±0.5 dB in amplitude and ±5° in phase has become a near universal standard both in academia and industry [1]. However, this almost omnipresent usage belies the fact that surprisingly few workers are familiar with what this implies for an actual antenna pattern measurement. The recent development of a novel computational electromagnetic (CEM) simulation tool that permits the simulation of "measured" far-field pattern data for a known CATR and test antenna combination [2] permits the careful examination of the behaviour of these three conventional CATR QZ specifications on "measured" far-field patterns for a given test antenna. Results are presented and discussed.