First document highlighted

The document that follows the first document made in a project is highlighted. Left undisturbed, that highlighted document can show where one started writing in a project. Is there a way to designate this document once a different document has been clicked on or created elsewhere?

Assign a Label or Keyword to it.

Thank you.
If I do this, it acts the same?

I’m not sure what you mean by “acts the same?” Applying metadata does not change the contents of the document, and only affects the Compile output if you want it to.

I am really unclear what you are wanting. It sounds like you want a permanent highlighting of the very first document you made in a Scrivener project. Not sure why you would want this, frankly, but…

Why not give it a special name?
Why not put a special mark in its title (*)?
Why not assign a special icon to that doc?
Why not assign it a Label (and enable the function that tints Binder items with label colors)?

Say there is one document in the Binder. Next, I create a second. The first document is highlighted like a breadcrumb. I would like to define a document to behave like this breadcrumb.