A lot of books give a question on YDSE by mentioning the phrase 'first maxima'. They don't mention 'first order maxima'. This causes a lot of confusion, whether they are referring to the central maxima as the first maxima or the first order maxima as the first maxima. I got a lot of questions wrong in my tests because of this confusion. So should 'first maxima' be considered as the central maxima or as the first order maxima?