Interesting thing was revealed by  The King of Fighters Official Facebook page few days ago. Turn out that the game contains “hidden command” that allows frame data to be displayed next to each key pressed in “Training” and visible in “Replay Data” modes. It turns out that the option was available since The King of Fighters XIV was released, but no one figured it out. SNK decided to take matter in their own hands and reveal it. You can check the full post with the instructions below.

 Hidden Command

Step.1
Enter the following command in the Main Menu: , then press X and △ simultaneously.

* Keys: X and △ in the case of a default configuration on PS4.
* For other controllers and configurations, please use the buttons assigned to the “Light Kick” and “Heavy Punch” attacks.

Notes about the “Hidden Command”:
* The command will fail if another direction than “” is pressed first in the Main Menu.
* The command will fail if buttons and keys are pressed during the command input.
* The command will fail if other keys than the two described above (“Light Kick” and “Heavy Punch”attacks) are pressed at the end of the command, even if pressed together with the correct keys.
* If the command hasn’t been successfully entered, please leave the Main Menu once, and return to it in order to retry.

Step.2
If the secret command has been successfully entered, confirmation white flash and voice / sound effects can be seen and heard in the same menu.
https://youtu.be/x6ZzprjIjlo

* Confirmation flash and sound effects will play each time you will enter successfully the secret command described above.

Step.3
If the secret command has been successfully registered in Step.1, frame information will now be displayed next to each key pressed in “Training” and visible in “Replay Data” modes.
* Please note that as this hidden command won’t be saved, please enter it each time you play a new game if you want to use this secret option.

Here is  the example of successful unlocking in The King of Fighters XIV.