Combine zucchini, onion, green and red peppers; sprinkle with salt; cover with cold water. Let stand 2 hours. Drain; rinse and drain thoroughly.
Combine remaining ingredients in a large saucepot. Bring to a boil. Add vegetables; simmer 10 minutes. Pack hot relish into hot jars, leaving 1/4-inch headspace. Remove air bubbles. Adjust two-piece caps.
Process 10 minutes in a boiling-water canner.
Makes about 4 half-pints.
Submitted by: CM