Mxsmanic wrote
What does "below the line" mean, apparently with reference to checklists?

At the "old" PanAm, the takeoff checklist was divided by a line into
those items that could be accomplished at anytime after the taxi CL,
and those items that must be done after line-up on the runway. While
in TO position, some pilots would call for the "Final Items" while
others would call for "Below-the-Line"....same result.

Bob Moore
ATP B-707 B-727
PanAm (retired)