Is the billiards championship also determined by the participants? If 70% are in favor of Russian, then it's "CIS." 30% are in favor of pool – is that not "CIS"? It's a silly comparison, of course, but the point is clear.

The point is clear. Strictly speaking, in Heroes, you can't hold a CIS championship, or a world championship and its surrounding areas. Only registered federations can hold championships. In chess, the championships are held by FIDE, in football by FIFA, etc. The name "CIS championship" was invented by Nagan. The idea of the tournament was that selections were held in different regions of the former CIS, and then a final tournament. Now, in essence, the CIS tournament has turned into an ordinary club tournament, which has become a tradition and is organized by the participants themselves, and therefore the participants choose the version themselves. The emphasis is not on the version, but on the players. The version is chosen based on the preferences of the participants, and not the participants are selected based on the version. So, in this case, CIS is more likely to be interpreted as sit-n-go :D