Opening classification is determined by the most recent book move made in a game.
If the position on the chess board is a known one from a recognized opening, the game is said to be of that type, regardless of how it got there. This is called a "transposition."
For example, in a Queens Gambit opening by white if black responds with a Slav Defense is the game labeled as Queen's Gambit or Slav Defense?
My question is will there be a certain point reached after a series of opening moves when one side claims the opening label. Or is there etiquette involved such as a well known black defense will always claim the opening title?
I apologize if this question seems confusing but if someone could explain how opening titles work I would appreciate it.
Thanks