Source of text in bleed area of PDFs for print?

I do not have FrameMaker here on this laptop.

Therefore only a few questions:

Is this the value of one or several variables?

Can you change the size of your document and then check, if this text gets shown?

FrameMaker can show details which are on hidden pages, e.g. text frames are on left pages. When you have a single-sided layout, you will see only content on the right page. Only when you switch to a double-sided layout, you will the content of the left page again.

Maybe FrameMaker will also store content which is hidden behind the margins of your page.

Of course you can also create text frames which are on the edge of a page and create a bleed effect. Therefore why not text frames behind the margins?