丁是丁，卯是卯 [－－－－－－－]

Jyutping ding1 si6 ding1 ， maau5 si6 maau5
Pinyin dīng shì dīng ， mǎo shì mǎo

Definitions (Wiktionary)
  1. phrase, idiomatic
    serious; careful; unaccommodating (in doing things)

丁是丁，卯是卯 [－－－－－－－]

Jyutping
Pinyin dīng shì dīng , mǎo shì mǎo

Definitions (CC-CEDICT)
  1. lit. to keep ding (the fourth heavenly stem) distinct from mao (the fourth earthly branch) (idiom)
  2. fig. meticulous
  3. conscientious
  4. unambiguous