Un-tab key for when tabs are inserted as spaces

[YellowBeast]

I personally prefer to insert tabs as four spaces.

It is helpful if the editor keeps treating the inserted spaces as tabs.
For example, Programmer's Notepad 2 uses Shift-Tab as the "un-tab" command, and it correctly removes multiple spaces that form tabs.

So it would be nice if the editor in Pelles C could insert tabs as spaces AND remove spaces as tabs.

[TimoVJL]

I personally prefer to insert tabs as four spaces.

I personally prefer you to read help files, after that just from menu Tools... -> Options ... -> Tabs

[YellowBeast]

There is a misunderstanding.
This thread is about the feature of being able to remove spaces as if they were tabs.

I mentioned my tab preferences to give context why such a feature is needed.
Backspace and Delete can un-indent code with hard tabs, but not code with soft tabs (tabs inserted as spaces).
I also like the idea of a un-tab key combination: Shift-Tab seems popular.