Thread for posting confusing functions

[Gedankenexperiment]

Originally Posted by ADoubleDot

From a DrNo spreadsheet:

I was thinking that might make more sense as 'if (A or B or C or D) and (long thing) then "Yes" otherwise "".' But it was just as unreadable. Jeese.

What really wins it for me is how you have cases for errors and blanks, as though that monster should be responsible for cleaning up after other cells.