it's what it's explained in docs
if a function expects file name, you either provide file name where the required data lives
or specify and operator (node) using op: syntax where function will find the data
so if op: is not specified, function will consider the string to be a file path

this is different from similar functions in hscript (detail, point, …) as they don't expect filename, they directly expect path to the operator, that's why you don't put op: in those

but you can as well just plug the geo to any of wrangle's inputs and reference using input index like detail(0, “myValue”)
or in 16 you can create spare input drag your node there and reference by negative indices like detail(-1, “myValue”)

Thanks Tomas,

Yeah, the docs do explain it. But for myself, sometimes need to hear it explained again in a different manner; Which you did.

Now I get it.