Hmm, "what a tangled web we weave." I would have to put a good degree of it back on the persons involved and use a 'universal' rule of highest rank. With exceptions.If you host a mixed gathering and need to arrange certain protocols how do you determine who is "Senior"
A. My former instructor retired at a certain Dan level and while I was promoted to certain Dan levels beyond his before him, I will forever consider him my Senior.
B. In other instances there may be those who started training after me, and may have promoted to certain Dan Levels before me in other organizations. How would seniority apply?
C. How about those who started before me, promoted to a Dan level or two before me then "retired " and never returned to training?
D. How about if they took a decade or two off and returned but are therefore several Dan Ranks below me?
A. I would use deference and acknowledge your instructor. But as an active practitioner, it is only fair that your rank is acknowledged in the relationship. As far as acknowledgement during or at the start of class, it would come down to who is leading the class for me.
B. Rank is rank. Highest rank 'wins'.
C. If they are not active, and I meet them casually, I shake their hand, I do not bow since that is a Korean convention and we are Not in a class environment. If they come to workout AND they are highest rank, refer to 'B' in an honorary sense. Bow to them at the start of class, then bow to the class in your normal manner.
D. Refer to 'C'. Hopefully they acknowledge they need time to get proficient again.