ANY-ARRAY! vs. ANY-LIST!

I wouldn't say I've had any association of that. But your point is taken that the existence of the newline markers kind of throw a bit of a distinction onto what the type is.

While I was hesitant to suggest the dialect usage of newlines, I've kind of changed my thinking on that... inspired by cases like the tuple and path test dialect:

"(a b)/c"  ->  [@(a b) c]
"(a b) /c"  ->  @(a b)  [_ c]

Being able to leave off a container there just to have a variable number of things on the right felt good. So I started wondering about what kind of signaling you would use in a dialect to say "continued on next line"

With .. and ... being a valid TUPLE!, they aren't necessarily bad options, if they're out of band from whatever your values are:

"(a b)/c"  ->  [@(a b) c]
"(a b) /c"  ->  @(a b)
                ... [_ c]

Back to your point though: it's an odd type. That oddity may speak to favoring what might be for some people a more unfamiliar term, vs. trying to mask it in something they'd presume to be dimensionless.