Albania and Norway has still lots of 230V 3-phase supply without a common Neutral wire. Here in Norway all new systems are 400/230V V with N. I believe that UK stopped useng such systems in 1948, so we are a litt bit after
230 V 3-phase used to be fairly common across the continent, although usually in a TN-S or TT configuration rather than the Norwegian IT. The 127 V were essentially a by-product and - at least post-WWII - not used for anything that I know of. They're related to the 220 V by the factor of sqrt(3) that exists in all 3-phase systems. I believe the Soviet Union or possibly even pre-revolution Russia also began electrification using IT supplies like Norway did, assuming that they were safer than TN or TT supplies in mainly timber houses (I only have one questionable source for that though).
My point still stands though. Each and every single voltage I've come across in the world is a multiple of either 50, 55 or 60 V or related to one of them by sqrt(3). I find it hard to believe that this is purely coincidence.
