@luckyfnlou - This does bring up an interesting question: exactly what does "not allowed to hold a short position" mean? What happens if you have an IC in an IRA and one of its short legs gets exercised after expiration? Seems like the broker would be required to auto-exercise the long (TradeStation certainly does this; in fact, you have to call them and specifically instruct them not to, if that is what you want.)
It is, of course, best to avoid the whole issue and close the position before expiration - but it would still be useful to know what your broker's policy is, in case you get run over by an 80-year-old lady with shopping cart and a desperate need for toilet paper.