Heckling in Ultimate

Today (April Fool's Day) is as good a day as any to point out that "good-natured heckling" is within the Official Rules of Ultimate (11th Edition):

Number 3 under "Ten Things You Should Know About Spirit of the Game" reads:
Heckling and taunting are different.
Ultimate has a long tradition of good-natured heckling. Heckles are friendly barbs, typically
from non-playing spectators. Heckling can be fun, but taunting is unspirited and wrong.
Harassing remarks after an opponent's foul call or close play are NOT heckling: they are
abusive taunts which create unpleasant playing conditions and often escalate to acrimonious
disputes.

WFDF's "Spirit of the Game" differs from USA Ultimate's version.