Erased from the wiki is bad. Which page was this?
I guess here (
Referendum) but the page hasn't been edited since it was created four and a half years ago. More a case that the information never existed than it's been erased?
I always thought that once you actually started a referendum, it would explain how the results would be tallied in-game? You know, just like when council/lordly elections show 'A simple majority was required, i.e. 1 vote.' with the results.
As to the OP's question, I would guess an absolute majority requires 50% support for a referendum option to pass. A qualified majority would require 50% of all those
eligible to vote to support a referendum option for it to pass. There could still be a simple majority in favour, but if only, say, 40% of eligible nobles voted, it will automatically fail.
Still, the only way to know for sure might be to initiate one of those referendums in-game :-P