Orbital energy E as a function of the metallicity [Fe/H] for 147 GCs (empty circles) with orbital parameters from Savino & Posti (2019) and a kinematical classification in Massari et al. (2019). The different panels show the position of NGC 6388 (red filled circle), NGC 6441 (black filled circle, panel e), and NGC 5927 and NGC 6496 (cyan circles, panel c). In each panel, GCs associated to different merger events or those that formed in situ (Massari et al. 2019) are also indicated. The acronyms have the following meanings: main bulge (M-B), main disc (M-D), low energy (L-E), Sequoia (SEQ), Gaia-Sausage-Enceladus (GSE), high energy (H-E), Helmi streams (H99), and Sagittarius (SAG).