As you might expect, travelling on the trains is subject to regulations, and they are listed on the TfL website here.
Queue jumping is banned
1.2) Any person directed by a notice to queue or asked to queue by an authorised person shall join the rear of the queue and obey the reasonable instructions of any authorised person regulating the queue.
Bringing burning torches to a protest is banned
3) No person shall smoke or carry a lighted cigar, cigarette, lighter, match, pipe or other lighted item on any part of the railway on or near which there is a notice indicating that smoking is not allowed.
Drinking alcohol is banned, except when it isn’t.
4.3) No person shall consume alcohol on the railway, unless expressly permitted to do so by the Operator in a particular area.
It’s forbidden to be ill on the trains
6.4) No person shall soil any part of the railway
7.1) Except with written permission from the Operator, no person on the railway shall, to the annoyance of any person: (i) sing
Don’t run up the down escalator
9.1) No person shall use any escalator on the railway except by standing or walking on it in the direction intended for travel.
Let other people off the train first
10.2) No person shall enter through any train door until any person leaving by that door has passed through it.
Do not drive a car on the railway tracks, unless a traffic sign allows it.
14.1) No person in charge of any motor vehicle, bicycle or other conveyance shall use it on any part of the railway in contravention of any traffic sign.
Pogo sticks are banned
15.1) Any person who enters or is on any part of the railway to which the public have access must be on foot (wheelchairs are allowed in a secondary clause)