New car registrations in Brunei begin with BA, and then the next letter increases by one every six months. So we had BAP, BAQ, BAR ...
However, they skip a few in the sequence, for various reasons. For example, BAI was skipped. I always assumed that this was because it sounds like 'pig' in Brunei Malay, and nobody would want to buy a car that had 'pig' as its registration; but my colleague tells me it is because the 'I' could be confused with 1. I'll need to check that -- on that basis, presumably BAO was also skipped, because the O could be confused with 0. I'll keep an eye out to see if there are any BAO registrations
Anyway, I always assumed that they would skip BAU, as it means 'smelly' in Malay. But it seems I was wrong: