This "guide" sort of thing is just to cover skips/glitches that were useful back in the day, but got obsolete due to route improvements, they are the following:

Manhole Skip - Found by me, @Kromer in May 5th, 2018.

The first major skip used in Any%, consists in a pause buffer trick that allows the character to clip through the manhole and get access to the sewer levels, ignoring both Chinatown and Waterfront stages, saving roughly 20 minutes, but got obsolete after Roof Top Skip was discovered.

Factory Skip (Level 1) - Found by me, @Kromer in November 25th, 2017.

Following the same idea of the previous Skip, this one allows the player to clip through the gate and skip the first level of the Factory stage.

This guide may receive updates in the future.