right, with ⎕DR I can do a heuristic:
If there's one string, `⍎ code`.
If the first thing is a string, `⍎ code Y1 [Y2 Y3...]`
If there is a single string anywhere `⍎ X1 [X2 X3...] code Y1 [Y2 Y3...]`
If there's more than one string, clearly error and force more typing.