TRIBES is a great program. I would encourage you to take a look.
I had a class that tattled one year...it drove me nuts!!! I tried to analyze why they were tattling, and it was all over the map. Some were doing it to get back at someone else. Some were doing it to get attention, whether the attention was positive or negative. Some were doing it because they didn't have any other strategies to deal with conflict. Some did it because they saw their friends doing it. Some did it because I reacted to it and didn't keep my cool.
When I could not take it any more, I put a sheet of paper on the board and a marker on the chalktray. The heading on the paper said "I tattled today!" As soon as a child tattled, he/she wrote his/her name on the paper, and could not tattle any more that day. This helped the children who needed to tattle several times per day...they could now only tattle once per day and they had to decide to use it right away or save it for later.
When a child tattled, I would say "Thank you for sharing your concern." Unless there was blood, I pretty much ignored the tattling. The issues were small, and students learned that when they tattled, I was going to ignore most of the time, so why tattle in the first place.
Another thing I did was have the guidance counselor come in over two weeks (every day) and teach lessons on bullying (perfect for the child/children who is/are using the L on the forehead...personally, I would be calling home immediately about this kind of behavior.) I wanted intensive teaching by the guidance counselor, so that is why I requested every day. The counselor showed many examples of what bullying looked like, sounded like, and felt like. She read books, the students did mini-skits, and they play-acted situations.
I also had the guidance counselor teach the class strategies they had to use before they could tattle. She had about ten of them...ignoring, walking away, I messages, etc. The class practiced each one through role-playing.
If you do not have a guidance counselor who can help you will this, you will need to develop your own lessons. I am sure there are many suggestions on-line for lessons you could teach.
Once they were taught these strategies and still tattled, I would say "Which strategy did you try before you came to tattle?" The child might respond "I ignored." My response would be "I am glad you used that strategy. It seems to me that you solved the problem all by yourself. Please add your name to the "I tattled today" sheet." If the child told me he/she had not tried a strategy, I would say "After you have tried a strategy, you may come back and tattle. Then I will let you put your name on the "I tattled today" sheet."
Another thing I would do is reward those who said positive things to others. You must hear them do this. They can not come running to you and say "I just said something positive to John."
A reward might be writing their name on a piece of paper, putting it in a bucket, and drawing five names at the end of the day to get a prize. (Start small...you may need to do this at noon and again at the end of the day the first and second week. Maybe by week three you can just do it at the end of the day.) Some students will get to put their names in the bucket ten times a day...others will not get their name in the bucket at all. Live and learn...
You will also need to use your report card and the comments section of it to let parents know about a child's bullying behavior. I am sure your report card has a comment about respecting others. If the child deserves an N for needs improvement in this area, then give the N!! Be sure to make a comment in the comment's section. The comment might be: "Your child often solves problems by using unkind words. Sometimes your child is the one who says these unkind words, and sometimes your child hears unkind words from others and responds by using unkind words. _______ needs to use other strategies to solve conflicts. These strategies might include ignoring, walking away, (list other strategies the child has learned)."
Another comment might be "Your child often tattles rather than solving his/her own problems. Our class has practiced strategies like ignoring, walking away, (list other strategies). I would like to have _______ use these strategies rather than tattling. It would be great if you could practice them at home so _______ becomes familiar and confident using them."
I would not use these comments unless the parent is aware of the problem. If I were a parent, I would want to know over the course of a grading period that this is an on-going problem. This will mean conferencing with the parent in person, by email, or by phone. If you see improvement over the course of a grading period, I would make a comment on the report card to this effect.
I noticed on the list of things you have tried, you did not mention calling home. Maybe you have tried this, and it didn't do any good. Maybe you have tried this, and home did not see a problem. Maybe you have not tried this...and I definitely would.
After intensive work with the guidance counselor and intensive training about bullying and strategies to deal with problems, I would let the class know that from now on, bullying will get a warning and then the child will be calling home/parent's workplace. Before this happens the first time, send a letter/email home to parents that tell them that the class has been having a great deal of difficulty being nice to others. Explain how students have worked with the guidance counselor, and what strategies they have practiced. Give specific examples of these strategies. Encourage parents to practice these strategies with their child. Then let parents know that from now on, their child will get one warning and then will be calling home/workplace. I would make sure this letter is returned with a parent's signature.
When a child has a problem, I would take him/her aside and let him/her know that if the problem happens again today, he/she will be calling home/place of work immediately while the rest of the class listens to the call. This is his/her warning. If the child/children bullies/bully again, I would help him/her dial the number and make the call. Before calling, the child should practice what he/she is going to say. You should also speak with the parent so think about what you are going to say. The rest of the class will get the message very quickly!
No matter what you try, you will have to be consistent. As soon as you change the rules for one child, students will see you as wishy-washy and take advantage of it. The student who has to call home is going to cry...too bad, so sad...don't give an inch. The child must call home. You set up the consequences and you must follow through!
Be positive...be strong...don't order a wig to cover your bald spot yet!!!
I hope these give you some ideas.