I'm dumb and need a little help.

Well since this came up, a question to the more knowledgeable members of this forum: In case you have several sources of curse on hit for a single hit and no source of additional curses, is there a set order in which the different CoH are applied? Like here, the CoH from skills is applied before the CoH from gear, is this always the case? What if a single skill is linked to two curses? What if you have two different CoH on your gear?