Metallicity as a function of the semimajor axis, a, for the full cluster sample but symbols colored according to the adopted classification (D14, D16 and D21): grey, orange, blue, green, red, and brown symbols represent clusters belonging to the Main Body, Counter-Bridge, West Halo, Wing/Bridge, Northern Bridge, and Southern Bridge, respectively. Squares depict the clusters studied in this paper and circles represent our additional cluster sample.