Materia smuggling

Materia Smuggling is a glitch found in Final Fantasy VII. The glitch revolves around using garbage memory to 'store' materia which can then be transferred to the party.

Setup
There are three flavors to this glitch, two of which work on all remastered versions (i.e. not PS1 version), and the third only works on the Steam port.

On the Materia Exchange screen, by placing your cursor on the final character's weapon, then losing a character due to plot reasons, the game automatically keeps the cursor in place, resulting in it opening on a garbage memory registry. This registry contains hexadecimal code which defaults to FF, or MP Plus.

Free MP Plus Materia
At different occasions during the game, you lose a character(s) from the party. These instances are ones where the party member disappears from the Exchange menu. The instances are: By doing the setup at these points, then triggering the flag that removes the character, the garbage memory becomes active and the two available MP Plus materias can be moved out of the garbage memory and into actual memory.
 * First Gold Saucer visit (loses Barret)
 * Post Temple Of The Ancients (loses Aerith)
 * Wutai Sidequest (loses Yuffie)
 * Jenova DEATH (lose a character who grabs Black Materia)
 * Post Meteor Summon, Pre Mideel (loses Cloud)
 * First Mideel visit (loses Tifa)
 * Northern Cave split up (lose whichever team members go other way)

Smuggling Materia into Wutai
It is possible to use this to smuggle Materia into the Wutai sidequest by putting materia from your inventory into the garbage memory slots in a prior instance, then retrieving them during the Wutai sidequest. Since Yuffie steals materia by priority, it is possible to 'protect' certain materias for use.

Smuggling Materia across saves (Steam only)
Due to a bug in the coding, it is possible to use the glitch setup above to transfer materia across save files. Simply initiate the glitch setup on an endgame file, and game over. Next, load up a save with fewer characters than the one just used. The glitch will now be active on File 2, allowing you to place materia into the garbage memory, however, the memory persists across saves. Place the desired materia into slots one and two in the garbage memory, then Game Over. Finally, load a new save (with less characters than File 2) and the glitch will be active again, having saved the materia stored in the memory.

Additionally, since the game doesn't save progress upon Game Overs, it is entirely possible to complete the process, remove the smuggled materia from the active party, save and then restart the cycle, in order to get multiple high level materia at the beginning of the game.