Overriding System Class Defaults

I read Setting default values for Xojo framework Class properties — Xojo documentation
It say:

Is there a list of the properties that we can change by doing this overriding?

Most anything that is a simple type (string, integer, boolean, double)

I tried Caption, Visible and others and can’t make those work.
It works with Width and Height.

Of what class ?
Each set of defaults has to be in a separate file named for the classname

Thank you Norman, I’ll try to explain.

For WebButton, I don’t like the Height of 22 and the Caption of Untitled, personally I think for consistency with Desktop apps, the Caption of the WebButton should be Button.

I created WebButton.defaults in Documents/Xojo/Overrides/WebButton.defaults with this defaults:

Height works, Caption doesn’t work.

Alot of controls in Xojo (at least on Desktop amd espcially iOS) are fixed in either height or width and cannot be changed.
I have found in “Xojo for iOS” many controls are restricted when in fact Apple has themselves applied no such restriction

Thank you Dave, yes, I’m working with Web Buttons for the most part.

The docs only mention ‘override default properties’, so I guessed that I can change things like Caption, Visible, Enable, but it doesn’t work. Width and Height work great for WebButton, WebPopupMenu, etc.