The "H" is for "Holy" ...Notice that people only add the middle name "H" when really aggravated. Parents probably teach us that ...
Many years ago, I also read a tongue-in-cheek explanation regarding the numerilogical "balance" of using "H" ... "J" = 10,
"H" = 8,
"C" = 3So ... 10+8+3=21, which is a very holy number,
because 3*7=21, and both of those are holy numbers.(grin) ~S~