Collins Chinese Dictionary Plus (3rd edition), 2011:
成文 chéngwén
I 名
existing writing
- 他抄袭(襲)成文。 Tā chāoxí chéngwén. He is copying existing works.
II 动
write;
(pt wrote)(pp written)
(pt wrote)(pp written)
- 这(這)些规(規)定必须(須)成文。 Zhèxiē guīdìng bìxū chéngwén. These provisions must be in writing.