i know... but i have:
main class domi 80lvl - 2lvl buff book,
subclass SPS 80lvl - 2lvl buff book
cardinal 80lvl - 4lvl buff book
titan 79lvl - 1lvl buff book
bd 79lvl - 0lvl buff book
... and never buy books and learne this skills
buff slots must give automatic on individually class check server settings