Using Text Storage to interrupt the door opening cutscene with swinging doors will allow you to regain control with altered collision. This collision is an intensified version of Chest Storage, where it is possible to climb steep slopes like with Chest Storage, but it is also possible to walk through most walls and objects. Some objects, such as the tree's on the path to Forest of Fairies on Outset, cannot be walked through though.
While in Door Cancel, the screen will usually fade out to either black or white. While pausing or opening the map, you regain visibility for a moment. The HUD still remains visible, so it is also possible to navigate with the mini-map. It's also possible to get door cancel while retaining vision, see Door Cance with Vision below.
The video below uses a wireframe hack to show what is happening while the screen is black:
Only a handful textboxes in the game can be used to cancel the door opening animation for door cancel. The known textboxes that have this potential are the following :
To superswim with door cancel, you can get dry storage after getting door cancel, but this means you need to get dry storage while blind. There are most oftentimes easier ways however: if you manage to go in front of a door with both camera lock and a textbox stored you then won't need to get storage blind.
You can climb ladders with door cancel by hookshotting to them.
Note: There exists another method of getting altered collision. See Chest Storage for more information. These two glitches are sometimes interchangeable, but Door Cancel is usually stronger.
If Link is holding nothing in his hand, there is a single frame where closing the textbox during the door opening animation will grant Door Cancel with vision, and this is usually what should be aimed for.
While it is best to do the frame perfect textbox closure to get Door Cancel with vision, there are also ways to remove the fadeout after obtaing the blind version of Door Cancel. You can remove the fadeout from door cancel by either:
On the japanese version, you can dupe a fire arrow to gain a little bit of visibility.
For both the swinging doors (for example on Winfall and Outset), or the big swinging doors (at Forsaken Fortress for instand), interesting things can occur if you store opening them. In particular, you can obtain a state called Door Teleport, where pulling out the wind waker or just entering any event will make you teleport back to the stored door. In all cases, the door you've used to setup door teleport on won't be able to be opened normally until you reload the area (however, this is usually not a problem if you can teleport directly into the loading zone or clip inside or behind the door).
The difference between this and Door Cancel is that to setup a door teleport you just need to press A to open a door while you have storage, or cancel opening the door as you're trying to open it with a textbox. For Door Cancel you must cancel the door opening animation in the middle of it, requiring some form of text storage.
If you store opening a large door, then simply pulling out the wind waker will cause Link to quickly slide mid-air to the door you stored. This can be used to clip through walls for example.
This same door teleport can be obtained on dungeon doors by closing a textbox (from a song stone or from KoRL) and then opening the door frame perfectly so that it remains in a state where it's trying to open but stays closed.
For doors that are not swinging doors, such as the doors inside dungeons, Door Cancel is not possible, and Door Teleport is frame perfect. However another trick known as Door Storage is possible.
When you store opening a dungeon door, the door freezes, and becomes unable to be opened. If you then open another door, one of two things will happen:
It is currently unknown how to force one of the two results, if it's even possible.
You can also cancel opening such a door with Text Storage. Inside a dungeon this can be used to load 2 consecutive rooms at once.