The meaning of the term “Chinese wall” is clear. It’s a virtual partition meant to keep potentially conflicted interests apart. What’s not clear, at least to me, is where the term came from. This post at WhatIs.com quotes Wikipedia, this way:

Chinese wall is usually said to be a reference to the Great Wall of China, erected over 2000 years ago to protect inhabitants from invaders. However, other theories exist. In a Wikipedia entry, for example, the author argues that the term probably derives from a diplomatic contrivance of the Late Imperial period in China: “…if a junior mandarin saw a senior mandarin on the road he was expected to bow and present his compliments. In Beijing this tended to happen quite a lot and so traffic was frequently blocked. Instead mandarins came up with a method of pretending they did not see each other on the road by the clever placing of a retainer with an umbrella. Because they did not “see” each other, they were not obliged to stop.”

Meanwhile Wikipedia’s Chinese wall article now lacks that passage, so that’s a dead end. I recall “Chinese wall” meaning a thin one: You can hear what’s happening on the other side, but can pretend not to notice. Still, not good enough. So I’m hoping one of you can point me to a source I can cite in the book I’m writing.

And if you’re wondering why I’m posting less these days, it’s because my nose is on the book’s grindstone.