Hiding is a game mechanic for the game Five Nights at Treasure Island introduced in the remastered version. As revealed in AnArt's files, it was going to be in the original demo but a memory leak with Gamemaker prevented the source code that includes this to build.
Holding the SHIFT button on the keyboard allows the player to hide under the desk in The Office until a Suit leaves The Office. A message will appear at the bottom of the player's screen that explains to hold shift to hide. Hiding has a 50/50 chance of working against a suit that goes inside the Office. But hiding under the desk for too long will cause Slester to attack the player.
Hiding has a 50/50 chance of working against suits luring the suits out of the Office.
Hiding is the only way to make Acephalous leave the office, however you have to wait under the desk.
Hiding also makes Purity leave the Office immediately.
When the Power is out, Shade The Face and Shade Oswald will leave if the player is hiding.
Hiding is also used to protect you against Classic Oswald when he's running in the Meat Freezer for reaching the Office.
When the power is out and The Face finds the player, instead of jump-scaring the player, The Face will wait until the power is on and the player will be locked under the desk.