In a large bowl combine squash and salt; toss to coat. Let stand at room temperature for 3 to 4 hours. Transfer squash to a colander set in a sink. Rinse with cold water; drain.
In a large stainless-steel, enamel, or nonstick heavy pot combine vinegar, honey, bay leaf, fennel seeds, garlic, crushed red pepper, and peppercorns. Bring to boiling over medium-high heat, stirring to dissolve honey; reduce heat. Simmer, covered, for 10 minutes. Remove and discard bay leaf.
Pack squash and oregano sprigs into hot sterilized pint canning jars, leaving a 1/2-inch headspace. Pour hot vinegar mixture over squash, distributing the whole spices evenly among jars and maintaining the 1/2-inch headspace. Wipe jar rims; adjust lids and screw bands.
Process filled jars in a boiling-water canner for 10 minutes (start timing when water returns to boiling). Remove jars from canner; cool on wire racks. Let stand at room temperature for 3 weeks before serving. Makes 4 pints.