@acer: Your interpretation makes sense to me.
Per your last paragraph, I will expect rtables to not get evaluated when passed as a parameter; effectively giving them temporary last-name evaluation type. At the same time, lists will get evaluated fully as the rationale for not doing so isn't present with the immutable structures like lists. This difference in behaviour is good to know and remember. I actually ran against the evaluation of lists already once, when I needed to get at the names of the elements of a list which was passed to a proc; I had to use the ::uneval modifier in the parameter definition of the proc to get at those names. So now I understand why. I do wonder whether all this is unnecessarily complicated, but then, I haven't done enough with Maple yet to make such a statement.
Anyway, I gained some more insight, thanks.