The figure enlarges the hot portion of Fig. 12 and displays the absolute shear ΔΩ vs. effective temperature for measurements by line profile analysis. Symbols identify measurements of differential rotation from line profile analysis as given in the caption to Fig. 10, but here assuming an inclination of 90^◦. In addition, the ranges of shear accessible to observation are indicated by short horizontal lines. The cases of α = 0.05 and α = 1 are distinguished by black and grey, respectively. These ranges are determined by rotational period alone, in a way that is given in Fig. 11. Therefore, the detectable ranges can not only be given for those objects which display differential rotation. Instead they can be assessed for all objects with the rotational profile measured, including the stars that are considered rigid rotators. Among these limits indicated by short horizontal lines, stars with periods longer than a day are distinguished from stars with shorter periods by dotted lines. The two solid (black and grey) flexed lines represent envelopes to the bulk of the limits. These are based on the maximum vsini observed which is most probably due to sini ≲ 1. Error bars are omitted for clarity. The dotted line denotes the upper bound on shear of F stars identified in Fig. 11. The dashed line reproduces the fit of Barnes et al. (2005).