SKU - Additional option in custom fields

[hazael]

What is it for (in image) ? How and what to use it for?

[pinochico]

is this VM3 and J3?
And where is setup every customfield?

I think this is SKU for child, but from this image I don't confirm, we use CF4All.

[hazael]

I also use CF4All, but not in every case.

This is what I see in the latest version of Virtuemart 4+ for Joomla 3/4
These fields appear when I select Custom Field Type: string

It is displayed in every product