Okay, thank you but I don't quite understand this:
"It is unclear whether progression is a standard part of the game or you are also describing a progressive chess variant of your game."
This chess variant is played according to the rules of progressive chess. This is stated in the rules - in the Move Progression (Progressive Chess) section.
Should I add the phrase that progression is a standard part of the game?
Okay, thank you but I don't quite understand this: "It is unclear whether progression is a standard part of the game or you are also describing a progressive chess variant of your game." This chess variant is played according to the rules of progressive chess. This is stated in the rules - in the Move Progression (Progressive Chess) section. Should I add the phrase that progression is a standard part of the game?