Commercial photography?

[Deleted]

On LU's site it mentions that you have to have a permit for Commercial photography and talks about the whole subject in a really roundabout way.
Since the subject of photography and the rules regarding it has been discussed recently on the board, out of interest, what exactly is the boundary between Personal and Commercial filming? If a random person was taking pictures on a standard, small camera to use in his/her possible Underground publication, then is this commercial, for example, as opposed to a major film project?

[Phil]

If the LU rules are interpreted in the same way as others, commercial photography would be defined as that by which you make your MAIN source of income.

If the book is a sideline, or you occasionally get paid for pics to railway mags, then it's private: once you get so good you can give up other work it becomes commercial.