Alpha, Bravo and Charlie aprons have 3 centrelines while the Deltas still only have one. If not advised use the centre for taxying in. When pushing back use the nearest unless otherwise advised. Except at night when only the Alpha apron has 3 lit centrelines. Above all ask ATC if in doubt. A 737 700 can use the three centrelines in the Bravos except when it has winglets when it is centreline only.
Confused? You should be!!!