Thanks for that. Interestingly enough, I was just reading some of the stories from the 4th "Honor Harrington" anthology recently, and one of the stories had "the most junior officer toasting the Queen" in it -- though the Manticoran tradition seemed to be slightly different, since it had just the junior officer initiating the toast, rather than being the respondent to an initial toast by the PMC.

It didn't occur to me that it was based on an actual tradition.