Hmmmm. I think I'll have a look in the school rules to check that out. I had to write them out once or twice <img src="images/graemlins/blush.gif" alt="" /> <img src="images/graemlins/mad.gif" alt="" />, and I don't recall seeing anything about knives or blades.
But then again, I might have to write those rules out again for "disobeying an unwritten rule"... (this is where I leave the keyboard and devise several systems for causing havoc within the school safety regulations...)