Writing five-character regulated verse requires attention to parallelism and tonal patterning.
Tips
culture
Per 《新华词典》: 形成于唐初。每句五字,每首八句,双句押韵 — 'crystallised in the early Tang; five characters per line, eight lines per poem, even lines rhymed.' The middle two couplets (lines 3-4 and 5-6) must be strictly parallel.
usage
Compare lengths: 绝句 = 4 lines (the short form), 律诗 = 8 lines (the standard form), 排律 = 10+ lines (the extended form). Regulating 'pingze' tonal alternation is what makes them 律 'regulated'.