[fmakunbound]

Do you mean, for example, a null node versus a missing node?

[ruricolist]

I mean distinguishing between `null`, `false`, and `[]` on the JSON side. Most JSON libraries for CL by default parse them all as `nil`. (ST-JSON excepted.)

[codr7]

I guess that means you can't generate false and [] either?

So this would be a good example the culture clashes I mentioned, handled badly.