Question Meaning of "initial" setting for visual element properties

Many properties in the UI-Builder can be set to a value called "initial".
(Like size, flex-basis, flex-grow, flex-shrink and others)

I wasn't able to find any documentation on that setting.

I know that there is a flex:initial value in the web version of flexbox, but since this setting
is also available for settings unrelated to flexbox i assume those are different things.

Could someone explain what "initial" does and when to use it?

 

I really don't know the details, but the Intellisense text can be seen in a editor for StyleKeyword.Initial:

 

So that would mean that it's purpose is to reset a style to whatever it's default value was I guess. It's just a bit confusing that you can also set this in UI Builder since for most styles the default is auto and you can also set it to auto.

I guess setting it to initial has the same effect as setting it to auto for those styles.

Thanks for your help.

 

Only for the sake of completeness: In another thread it was especially mentioned what "initial" means and what it is used for:

(Thread: https://forum.unity.com/threads/ui-builder-has-very-flawed-ux.1307613/#post-8275050)