If a sentence in "Cha Jing"(The Classic of Tea) saying 'Tea is a good tree in the south ("nanpo," written as 南方)' is deemed to be the source, the pronunciation should be 'Nanporoku'; if it is deemed to come from Sokei NANBO (written as 南坊), the author's name, the pronunciation should be 'Nanboroku' with a voiced consonant.
『茶経』の「茶者南方嘉木」を典拠とする場合は「なんぽうろく」となるが、著者である南坊宗啓の名であるとする場合は「なんぼうろく」と濁音になる。