You may have noticed the rules mention a few glitches and how they are banned. These are some of the most game-breaking glitches in the game and have been patched out of the most recent updates of the game. If you are playing on the latest update, then you shouldn't worry about these glitches too much.
Reverse Cutscenes // Patched in version 1.70 Reverse Cutscenes is a glitch that allows you to bypass cutscenes that would normally prevent progression. By entering a cutscene trigger in a particular manner, you can cause cutscenes to reverse your direction, which will allow you to bypass these triggers.
Parallel Universes // Patched in version 1.80 Parallel Universes are out of bounds areas that replicate a certain area. It replicates the items that exist in the area but does not have any collision. It's a bit difficult to explain, but by entering a Parallel Universe, you can collect all the items in the area extremely quickly by bypassing all collision that would normally exist in the area.
Spring Exploration // Patched in version 1.91 Spring Exploration is a collision glitch activated by jumping on a spring as it screen transitions. Currently there is only one known spring where this glitch can be activated. While in Spring Exploration, all collision can be bypassed allowing you to pick up any item and skip nearly every boss in the game with ease.
In a speedrun, these glitches are exceptionally broken, allowing things such as skipping to the end of the game. These glitches are still used in legacy speedruns, which can be found under the miscellaneous section, but since they have been patched out of the recent versions of the game in addition to being completely game breaking, they have been banned from the main categories.
For more information, feel free to visit the Rabi-Ribi Discord server and ask.