ZRH From Switzerland, joined Nov 1999, 5563 posts, RR: 38 Reply 1, posted (10 years 2 months 2 weeks 3 days 17 hours ago) and read 2428 times:
I only know that at the A- and E-gates you can park different numbers of aircrafts depending on their size. At A 48 and 46 (for example) they can park two wide-bodies or three narrow-bodies at the gates A 46-04-48. I think that is why the gates are different numbered. You could say the A 4X are the main gates where you can park any aircraft of any size. But when they use the A 0X gates in between they only can park narrow bodies. I know it is a little bit difficult but I hope you understood it. I am not 100 % sure but almost. Perhaps the a.net member "Unique" could tell more because he works for the airport authority.
BTW the gate numbers from the inside, for the passengers, are differently numbered.