There is an interesting GRA on ???? ?????? where Rashi says that a yud is missing and a pilegesh has no kesuvah. What is the connection? ???, ??? and ????? Hashem ?-?-?-? resides in it. The yud in ish, the heh in ishah and the vov heh in kesuvah where it should have been called ???. The pilegesh has no kesuvah so the vov heh is missing by halfing the shem as ??? ??.
