1. Fill a large pot with cool water, add in the salt, and place over high heat.
2. After 10 minutes, or once the water comes to a boil, add in the pasta then stir well.
3. Boil the pasta for 10 minutes, then strain the water immediately.
4. Peel and shred a carrot, then chop the onion, pepper, and celery into very small pieces.
5. Get a large mixing bowl, add in the mayo, relish, mustard, vinegar, sugar, and seasonings, and whisk well.
6. Then add in the chopped vegetables, and stir well.
7. Add in the macaroni, fold well, then garnish with parsley flakes.
8. Cover with plastic wrap and set in the refrigerator to chill.