Question on FAQ about coordinate system

@eelik in this post: Coordinate system, grid and origins in Pcbnew (especially version 5.99), near the beginning you said:

It is important to know that these affect only the visible coordinates in the graphical user interface. The internal coordinate system and the board file aren’t affected. However, the drill/place file origin may affect the footprint position file and the drill file outputs.

I’m not following what you mean by this statement. Can you please elaborate?

I think you are saying that there is an option to flip the Y axis direction and that is on the user facing side but the KiCad internal data storage is staying the same.

So, if you flip the Y axis direction i.e. it increases from bottom to top of the screen, and then go look in text files the positions you see for components will not be the same between what the UI said and what is in the file. Yes?

As I type this, it feels like what I say cannot be true because this ripple into interest areas. For example, I write a tutorial with the Y axis flipped and put in a description of locations to place elements and then you create it with the Y axis not flipped, it is going to be a bad situation. Almost sounds like an I Love Lucy episode.

I must be missing something here.

You’re not missing anything, you understood correctly.

Yes, misunderstandings when communicating about designs is possible. The used coordinate system should probably be standardized inside a company etc. and tutorials and other public documents should use the default system. But I don’t see it much different from for example customizable toolbars. Customizations should be kept private or standardized across parties in communication.