[jtur88]

Designations like 6-4-3 or F-7 have no official significannce. The player himself is credited with the putout or the assist, Those numbers are writteon in the scorecard only so the scorekeeper can, at the end of the game award assists and putouts to the correct player. When an unusual shift is used, the number is merely a shorthand to point to the player.

It is not obligatory to formally announce a players position, except pitcher. All others may occupy any place in fair ground. One player can be in foul territory, behind the plate, but it does not have to be the player listed as the catcher.

As for career statistics, a player is considered as playing a certain position if he and another player switch, but not if he simply occupies an unorthodox spot when other players remain at their normal spots. Cincinnati once used a Musial shift, with four uniformly spaced outfielders. But the extra outfielder who went out there was not given a career game as an outfielder.
However, if the 1B is the player who usually catches a knucker, and a knuckler is brought in in relief, and the 1B goes back there, and the C goes to 1B, that constitutes a position switch, even if they go back after one batter.

Special rules apply to the pitcher, so if a pitcher is involved, than there must be a formal announcement of who is the pitcher in the game.