Initial period distribution in star clusters (solid line; Kroupa 1995b,c), the observed field G dwarf (grey histogram plus Gaussian distribution; Duquennoy & Mayor 1991), and a theoretical binary period distribution for Galactic G dwarfs (dash-dotted line; Marks & Kroupa 2011). The period range between the dashed lines is the range of binary periods accessible in the spectroscopic survey by Carney et al. (2005). The percentages in the legend show the binary fraction within this range for the respective distribution. The region between the dotted lines is the location of the hard-soft boundary for a typical present-day GC (M = 10⁵ M_⊙, r_h = 3 pc; see Sect. 2.2). We note that f(log₁₀P) = N_b(log₁₀P)/N_cms, where N_b(log₁₀P) denotes the number of binaries in the orbital period bin log₁₀P.