Woops. Yeah I messed up the translation of hex digits. That's what I get for not sleeping more than a few hours this week. (wooooo)
As said above, hex digits after 9 will sequence A, B, C, D, E, F and then cycle back into numbers 10, 11, 12 etc., up until 1A, 1B, 1C, etc.
Still have not found...