So for instance, can I use the account I have registered here on mu-43 on one of the other ones of Amin's forums? This question isn't really for me as the only cameras I have now are m43, however I'm planning on introducing a work colleague to these sites. He's a big photography nut, has owned Leica M and Nikon F mount gear for many years, and has just supplemented it with an RX100 last year, and after seeing my PEN at many work events, has itched the scratch and bought an EM10, which he's loving, especially with the 14mm he got cheap from a kit split on eBay. So he'll probably want to join up to mu-43, SC and LeicaPlace, all with the same account. Is this possible? Or does he have to register separately for each one and hope he can get the same username on all three?