First column repetition

Does this very first column bearing an icon has a code like other tag fields do? So that It can be used to see icons of files not only on the left edge?

The first column that I can see in the "modify colums" dialogue is a user-defined one.
So I doubt that the icon column can be addressed.

Yes it's true, that this first obligatory column is not listed in the "Customize columns" section

But it doesn't necessary mean it cannot be doubled. After all, you can create your own fake tag field. So I wonder is there an instruction that could be put as a Value / Field

By the way: what is the difference between Value and Field? I always put the same content in all [so also in the "Sort

"Value" describes that what you see
"Field" describes the object where the data is stored.

So if you leave "field" empty, you get a readonly column.
Or if you want to have a value of some kind like $len(%title%) then you enter that in "value" but leave "field" empty.

The "Sort" field can set the sorting string, e.g. if you regularly sort by album and track but you have experienced that you usually have to click twice (first on Track and then on Album) to get the right sorting, you can enter
%album%$num(%track%,2)
in Sort for the column Track and every time you sort by that column, the string
%album%$num(%track%,2)
will be used.

After all, Florian had to put something in it to display those icons

That is such useful; right along with for example ARTIST tag displaying

%artist%(%title%)

So thank you very much

I've tried something as simple as putting

%_icon%
%icon%but I had no luck

I've made a request for such option: /t/18406/1