Help understanding two file chooser strings

[christian kirbach gmail com]

Good evening,

I am kindly asking for help understanding and interpreting two English
strings in gtk 3.24
They are part of the GTK file chooser dialogue, if I am not entirely
mistaken.

"Browse Header Revealer"
"Browse Header Stack"


'Browse' is a verb, no doubt.
But what exactly is a header revealer and what is a header stack in the
file chooser dialogue?


Regards
Christian