the Q-Tip
The 'Q-tip' is not required, and some people dont like to put them, as they give the weapon even worse balance than it would have otherwise, but swords without the Q-tip dont last nearly as long, because the end of the pipe destroys the foam at the tip of the sword, and makes it unsafe.  Shortswords dont need a Q-tip because of the short length... the shorter the weapon the less leverage there is to hit hard, so the tip lasts long enough without the added support of the Q-tip.
I mentioned that it is politely called the Q-tip, and you may wonder what else we might call it.
well... what do you THINK we call it??
hehe