Yum, food.
I'd have to say that most punishments at school, of any form are unneeded. So someone doesn't have their shirt tucked in / homework done / diary signed by parents / hair the right colour / correct length socks (the "list" goes on)(not that they actually use a list, not that us students have access to anyway, as far as we can tell they can basically just make up anything and get away with it), are you going to write a note for their parents in their school diary, make them pick up rubbish, or keep them back at school on detention one afternoon? Probably if you're a teacher at my school. But do these "solutions" actually solve anything? Do the students know why these rules are in place? Do the teachers even know why they are there?
No (Well the teachers may know but some of them "wouldn't have the time" to explain it, besides you might get a harsher punishment for talking back (with a few).).

Punishment is never the best way to solve a problem. It only reinforces the idea that you need to be obediant to an authority, instead of the idea that we are all equal.

Rather than punish people, schools should:

1. Makes sure that:
   
   • all students are aware of ALL school rules,
   
   
   • students have access to these rules in a written form
   
   
   • and that students are told of and have access to the justifications of these rules.


2. Give students the opportunity to work with the school in the continual development and review of a set of school rules, thus providing a perspective that represents the student bodies best interest.


3. Give students the opportunity to:
   
   
   • justify and explain their actions when a disagreement about behaviour occurs,
   
   
   • sit down with members from the school community to discuss their actions
   
   
   • not be dismissed or handed a quick fix solution to any problems,
   
   
   • and encouraged to take an active role in the course taken to resolve any issues

I was persecuted once for being in a water fight. Both parties had no complaints, but nontheless a prowling teacher seemed to think the behaviour extremely unacceptable, worthy of both a note in the diary and an afternoon detention 100 papers (picking up rubbish). This punishment did nothing other than to amuse my parents at the "seriousness of the offence" and to make me more determined to change the way in which the disciplinary system at my school works, namely:
the teachers have a few options, it's up to them to decide which course of action to take, influencing factors may include: age, height, gender, personality, appearance, personal experience (includes vendettas), mood at the time, weather, day of the week, etc. (the list is almost as long as the "list" which outlines the schools punishable acts ... I mean rules).

It is simply unfair. How can a school whos motto is "Act Justly" openly flaunt this ideal?

Who knows.