1Cook macaroni according to package directions; rinse and set aside.
Mix the mayonnaise, vinegar, mustard, sugar, onion salt, salt and pepper together in a bowl. Stir until well mixed.
Mix the dressing together with the macaroni.
Chop the celery and peppers; add to the macaroni and dressing. Stir all ingredients together until evenly distributed and coated with dressing.
Refrigerate until ready to serve.
I usually add onion, and chopped eggs. Also, I always make extra dressing, as the macaroni absorbs a lot. You don't want it dry.