I am reminded of a saying I heard often in Mexico:
"Todo es prohibido, todo es posible." ("Everything is prohibited. Everything is possible")
During a three day stay in a Mexican prison in Chiapas (the state that borders Guatemala) I was not there long enough to see a lot, but had the sense of tremendous , , , flexibility in the application of rules. Furthermore, I work regularly with a Mexican prison SWAT type team in the state of Mexico (see the clip on our multimedia page of the day when I met them). I remember one conversation after I had shown our DLO Dogcatcher defense against the prison sewing machine. I was asked about reverse grip attacks. As the interaction continued, I realized that they were not talking about an icepick type of attack, but a reverse grip attack with the blade laying along the forearm. This tends to be a slashing attack instead of a thrusting attack which suprised me quite a bit. Thinking in American terms I asked how the cons made good edges. "Oh, we're not talking about shanks made here in the prison they explained, but real knives that get in through corruption" they explained.