Stale Triangle Reference Manipulation
Stale Stored Triangle Abuse is a classification of glitch where a world map entity has stored triangles that point to triangle data that is stale, i.e. is no longer pointing to the same triangle data it original was since the data was replaced without the pointer being updated or removed.
Methods
It is currently only known to be possible to get a stale triangle on the current player character (only Cloud/Tifa/Cid), and not on any static object, vehicle, or Chocobo. The only known method requires a Chocobo that the player can mount. Normally, this is only possible by using a chocobo the player has caught and penned, which is only available after the Highwind has been unlocked, and by then, there is not much use in being able to traverse the world map like this.
Using a Chocobo Pre-Highwind
There are a few methods to be able to dismount and/or mount a Chocobo prior to obtaining the Highwind
Kalm Failsafe Abuse
Entering the area outside Mythril Mines activates a flag that results in Cloud telling the Chocobo to stay when dismounting instead of it running away if the player has a Game Moment under 364, . This is to ensure the player has a way back to get to Kalm if they access this area before completing the flashback sequence, as opposed to being trapped on the other side of the marsh with no standard method of bypassing the Zolom. This flag is normally deactivated when traveling away from this area, so this failsafe can normally only happen when in the area just outside Mythril Mines.
Zolom Glitch
If the east side of the swamp edge was touched last and the player moves onto the west edge at the same time as activating a battle with the Zolom, the chocobo and player are spawned on the east side but with the flag activated, allowing them to dismount and re-mount the Chocobo anywhere in the Midgar area of the map.