Prompted by the current thread concerning lounge overcrowding. There is some minor debate about what a 'clean' and 'dirty' passenger is. Now I have my own view about this of course . However in the context of passenger status in the terminal, what exactly is dirty? I thought once you passed security you had been cleaned. But it appears if you transit between terminals, in some circumstances (if you are bussed back from B to A for example) you may become very dirty indeed!

Could a staffer clarify?