The paper discusses the use of intensity quotients and differences in absolute structure refinement using single-crystal X-ray diffraction data collected with Cu Kα radiation for 23 crystals. Several methods were tested, including conventional refinement using an inversion twin model, estimation using intensity quotients in *SHELXL2012*, estimation using Bayesian methods in *PLATON*, estimation using restraints consisting of numerical intensity differences in *CRYSTALS*, and estimation using differences and quotients in *TOPAS-Academic*. The conventional refinement approach yielded accurate values of the Flack parameter but with high standard uncertainties. Other methods also provided accurate values but with much higher precision. Absolute structure was established in all cases, even for a hydrocarbon. The procedures that explicitly code restraints in terms of other structural parameters enable the Flack parameter to correlate with these parameters during refinement, improving the precision of the Flack parameter. The paper concludes that the potential problems associated with a lack of correlation between the Flack parameter and other structural parameters are not significant in absolute structure determinations of light-atom compounds, justifying the use of post-refinement algorithms provided a complete set of Friedel pair intensity measurements is available.The paper discusses the use of intensity quotients and differences in absolute structure refinement using single-crystal X-ray diffraction data collected with Cu Kα radiation for 23 crystals. Several methods were tested, including conventional refinement using an inversion twin model, estimation using intensity quotients in *SHELXL2012*, estimation using Bayesian methods in *PLATON*, estimation using restraints consisting of numerical intensity differences in *CRYSTALS*, and estimation using differences and quotients in *TOPAS-Academic*. The conventional refinement approach yielded accurate values of the Flack parameter but with high standard uncertainties. Other methods also provided accurate values but with much higher precision. Absolute structure was established in all cases, even for a hydrocarbon. The procedures that explicitly code restraints in terms of other structural parameters enable the Flack parameter to correlate with these parameters during refinement, improving the precision of the Flack parameter. The paper concludes that the potential problems associated with a lack of correlation between the Flack parameter and other structural parameters are not significant in absolute structure determinations of light-atom compounds, justifying the use of post-refinement algorithms provided a complete set of Friedel pair intensity measurements is available.