Disconcerting acts or words

[MJT]

Originally posted by tempestos
We were having a little debate last night and I was wondering if anyone had any official interpretation material on this issue.

Rule 9-5-1d states that it is unsportsmanlike conduct for B to use "disconcerting acts or words prior to the snap in an attempt to interfere with A’s signals or movements."

My question is what is considered a "disconcerting act" as opposed to "word." Can it encompass physical acts meant to draw the offense into a false start (e.g., running at the line and stopping before the neutral zone), or is it limited to cadence issues.

As a follow-up to this question, is there ever a foul against B for acting in a manner meant to draw A players into a false start?

The NFL and NCAA has rules regarding the defense causing the offense to move, with special guidelines on where the defender is and who on the offense moves, but the NF does not. Therefore the defense cannot cause the offense to foul by faking a blitz.