T in Binder Content Icon

The first icon in the Binder is blue and has a “T” in it, and says “Content”. I attach a screen shot.

I did not put it there; the icon in blue and “T” and “Content” appeared when I first opened the program to create a new book.

How did it get there and what does it mean? Not in the Scrivener Manual under icons, not in in CHANGE ICONs.

Does not seem to do anything in particular or make any difference.

Anybody know anything about this?

The T stands for Template. It is a document template.
Which part of the Binder is visible in the image? Template documents are usually found in the Research section, to be used as templates for documents in the Draft section.