Here's a letter in the forum page complaining about cats in HDB flats and more importantly that the rule doesn't work - which it doesn't. Does anyone besides the HDB (and people who complain to them) still trot out the cats are nomadic rule? The fact is anything can be 'nomadic' - so are dogs, or babies left unattended. The problem is the irresponsible owner - and honestly the owner is just being smart. If cats are not allowed, then the cat which wanders isn't IN the flat and hence he is not breaking any law.