Is "白皮书" a good translation of "open letter"? Looking through twitter today I came across this tweet that says:

加拿大前六个部长上白皮书，要求释放王炳章 Six former Canadian ministers call for release of jailed Chinese dissident in open letter /via @globeandmail

The original article is in English, where they use the term &quot;open letter.&quot; The Chinese translation is seeming just from Wang Bingwu where he rendered it as &quot;白皮书.&quot;
This translation doesn't make much sense to me, as 公开信 is a perfectly common 1-to-1 translation for &quot;open letter.&quot; And 白皮书 is just a translation of white paper. But, perhaps there is something to this that I am missing.
Is &quot;白皮书&quot; a good translation of &quot;open letter&quot;?
No, as stated in your post : 公开信 is a perfectly common 1-to-1 translation for &quot;open letter.&quot;; while &quot;white paper&quot; is a specific term for a type of government-issued document or business to business document, and it is always translated as 白皮书 in Chinese
The function of 白皮书 is different from 公开信. Translating 'open letter' as '白皮书' is a mistake.