Spark, the STGI pink sheet trader told me that CMKX is a "non qualifying piggyback issue" that could not be shorted, much less naked shorted. The reason is that the MMs can't buy or sell CMKX for a profit, they can only facilitate a trade between buyers and sellers, and profit off the spread.
99% of all the posts on all the boards are incorrect regarding this, and I will take the word of an actual pink sheet trader over anybody else on an anonymous BBS.