In a small bowl, whisk together the mayonnaise, vinegar, salt, pepper, sugar, and caraway seeds. Slice the cabbage in half through the stem end. Remove and discard the core. Thinly slice the cabbage to create long, thin shreds. Grate the carrots on the large hole of a box grater. In a large bowl, combine the cabbage, carrots, scallions, and parsley. Add the dressing and toss. Cover and refrigerate for at least 1 hour before serving.