[Boatanchors] Query about 73 & 88

[HL1FB]

This is HL1FB, Korean Amateur Radio League International Relations.
There was a discussion about the proper use of 73 & 88 among Korean hams.
When a male and a female are finishing a QSO,
is it appropriate the male say 73 or should he say 88? And the female 
say 88 or 73?
I was given a task to clarify this and find international stand way of thier usage.
Or does someone know where I should inquire about this??