Five regimes for the concentration dependence of the polyelectrolyte peak in salt-free polyelectrolyte solutions: (i) Infinitely dilute, electrostatically uncorrelated ‘gas-like’ regime, 0 < C < Cκ; (ii) dilute, electrostatically correlated ‘liquid-like’ regime, Cκ < C < C*; (iii) semidilute, C* < C < C**; (iv) concentrated, C** < C < C***; and (v) hydrated melt, C*** < C. The values of the exponent δ in km ~ Ĉδ for the various regimes are shown in the figure. The prefactors in the two regimes of 1/2 slope are different.