>>56857927For regulation, TCPi would just name which expansions were legal up to that point, but this became a hassle, so they came up with the letters instead.
The only single mark that's been consistent among all non-booster cards is the black star promo mark, so if you want some consistency among your collection you could do only promos.
>energiesThese are the only cards without a regulation mark, and you can use any energy from any expansion as long as it has the same back and in the language(s) permitted in your area (for sanctioned tournaments).
Apparently it seems TCPi wants to homogenize and clearly define each card, starting with SV, so every card has as much marks and info as possible now, even energies. Meaning it's possible from this point on that cards will be more consistent throughout generations, but don't keep your hopes up.
