Dear Mr Azar, please take a look at pages 22 to page 24 of the guide .http://www.ind.homeoffice.gov.uk/6353/11406/guideannew.pdf

If you only received a caution (warning) from the police and the matter ended there, you should be okay.

If you were charged with an offence, you should declare it on the form. A minor offence may be overlooked by the HO. Do not attempt to hide a conviction as they may find out and it will go against you

It is a little difficult to understand exactly what you are trying to say but I am trying. if you were charged with a criminal offence you would have been told so and you would have been read your 'rights', that is...."you do not have to say anything but anything you do say can be used in ......." etc.

Did this happen to you? Were you given a fine? Did you have to appear in a court of law?

From what you say, it does sound like you were only given a caution so it should be ok.

Dear Paul ,Thank you yours  advices sinceres and clears .so I would like to know what mean criminal convictions ,if the Police gave you a simple warning doesn't go to the criminal bureau because the themselves the Police confirm for someone who used a ticket for the train belong another personn./ In this case this person can apply his naturalisation or not .