Comparison of line strengths (S) of electric-dipole transitions for ions spanning the sequence. For Ne⁵⁺, MGB01 corresponds to the MCHF calculation of Mitnik et al. (2001) for transitions among the lowest 20 levels, while “up-triangle” symbols correspond to the data from the MCHF/MCDF collection⁶. For Ar¹³⁺, comparisons are made with the grasp calculation by Aggarwal et al. (2005) and with the autostructure calculation by Ludlow et al. (2010, hereafter LBL10) for all transitions amongst levels of the n = 2 configurations. The “ × ” symbols denote transitions among the lowest 20 levels. For Fe²¹⁺, a comparison is made with the MCDF calculation (Jonauskas et al. 2006) and that of Badnell et al. (2001, hereafter BGM01) for all transitions amongst levels of the n = 2 configurations. The “ × ” symbols are the same as for Ar¹³⁺. For Kr³¹⁺, we compare with the grasp calculation by Aggarwal et al. (2008). The horizontal dashed lines correspond to an agreement within 20%.