The cited forum post was not mine. I was only showing where I first saw the “file” and “move” actions mentioned.
Also, I cited to the wrong post. This was the one where BF used the word “File” — not in the actions, my mistake, but in the search criteria. I was trying to do a negative content search, like the poster here:
I did not understand how the word “File” made the “!” lookahead expression work: