[GavinMcG]

I was focused on the etymology; the actual usage of "ultrasonic" is generally confined to high pitches, not low.

Worthwhile point still, though I wouldn't have responded had the commenter not stated a specific incorrect definition. How does this connect to OPSEC though?

[ddingus]

Indeed you were.

The relation goes right to threat and solution scopes. In this case, someone working from an incomplete definition may well also work within an incomplete set of greater assumptions.

There is what it could mean, what we take it to mean, and what it does mean.

Where those overlap or not could have a significant impact on behavior.