 While embracing all, or most of, the "lushi" rules and regulations the "pailu" allows for a number of linked couplets with no maximum upward limit.A strict emphasis on formal parallelism is typical of the "pailu" form.Poems based on traditional structures, originally meant as lyrics to go along with particular musical tunes or scoring, included in the fixed tone-pattern forms are the "ci", "qu", and "yuanqu".