Increasingly, Courts are understanding that clothing that depicts sexual acts, coarse language, bodily fluids, or offense and bigoted messages disallows an appropriate educational experience. One response to this is a school dress code at one end of the spectrum, and school uniforms at the other. One can debate the efficacy of these provisions, but the basic difference is that the Tinker case was classified as a non-offensive protest (a black armband) as a Constintutional right, but blatantly offensive images or clothing that hinders learning, is unproductive and schools have a clear right to regulate that behavior (State Court and Lower Federal Court Decisions). Moral/Ethical- By the time we reach school age we have a basic understanding that there are often consequences for our actions. Within the model of classroom management there are various ways a teacher can model behavior, modify student's behavior, and change the manner in which that student views themselves and the world. Numerous examples of this are using intimidation and sarcasm to correct a student -- embarassing them in front of their peers; refusing to call on excited students who continually raise their hands, demeaning oral reading or answers with comments designed to hurt emotionally, and causing disciplinary headaches for no reason other than control (e.g. setting a student up for failure). Of course, these are extreme examples, and focus on attribution theory in the classroom, but they are certainly ways of controlling behavior, albeit causing other behaviors perhaps just as unwanted (Foote).

Instead, though, why not use this same theory in a motivational manner to ensure success and prevent poor behavior before it starts. Certainly, there are times when children may need a "time out," or if particularly disruptive, consequences such as taking play time away if there is too much talking, etc. But studies have clearly shown that by emphasizing the positive; "You put a lot of work into this," "Thank you for sitting quietly," "Yes, that's right, what else could you think of," etc. one has a far better chance of modifying and rewarding positive behavior rather than punishing bad behavior. In fact, studies even as far back as the 1960s show that...

From a personal stance, I would hope that my school had a dress code. However, at the beginning of each year it is important to have the students participate in a Room Constitution that outlines heavioral rules, respect issues, limits and consequenes. If the students participate in this, they are more apt to model those behaviors and buy into the process. Similarly, instead of setting up children for failure by starting lessons with, "How many know this," start the model with definitions on the board or overhead. "Today we are going to learn about x, y, and z. I will bet some of you have experience in x, y, and z, and w'll use that experience in a bit." Then, as much as possible, use Bloom's model to move from rote knowledge to questions that involve higher levels -- synthesis and analysis. Praise each answer; find something good about each comment -- this encourages children to comment. If one says, "No, that's not right," there is an implication of criticism and futility. Finally, understanding that we still live in a litigious environment, set up fair but enforceable rules; communicate these clearly to students and partents during open house of conferences. Firm but fair, and always consistent is a better rule for long-term success.
RESOURCES

Foote, C. "Attribution Feedback in the Elementary Classroom." Journal of Childhood Education 13.2 (1999): 155+.

Moser, J. "40 years After Tinker v. Des Moines, Parts I and II." 23 June 2009. Des Moines Examiner. October 2010 .

Schneider, M. "Linking School Conditions to Teacher Satisfaction." August 2003. Edfacilities.org. October 2010 .

"State Court and Lower Federal Court Decisions." Jounral of Law and Education 32.1 (2003): 92+.

Tinker v Des Moines Independent Community School District. No. 393 U.S. 503. U.S. Suprement Court. 1969.

Torrance, E. Rewarding Creative Beheavior: Experiments in Classroom Creativity. Englewood Cliffs, NJ: Prentice-Hall, 1965.