philbky
I think you will find that the OP question was answered before people started talking about chemtrails etc.
It was answered in varying degress in post numbers 2-6 inclusive. Yes, even the bit about buses and the two word answer of Flow Control were valid answers.
Just because someone does not post links to airspace maps then quotes chapter and verse of airspace and/or sector operating procedures (which are actually classified as being commercially restricted) does not mean the question was not answered.
It was a simple question, it required and received a simple answer.
The orignal poster actually states he/she found the info about chemtrails interesting so in fact they have been given an insight into something else (however far fetched), that they might never have heard of.
Thats the beauty of the internet, you can stumble across many different ideas/opinions - a lot of them rubbish but still interesting.
Maybe you should leave the policing of PPRuNe to the moderators. Or even better, leave the answers to the professionals that you so casually sneer at.