macros.flan says which of the two spellings it is

test/programs/macros.flan

@@ -5,9 +5,12 @@
 ;;;; parsed. What arrives here is the expansion; nothing at run time knows a
 ;;;; macro was involved.
 ;;;;
-;;;; A macro takes one parameter, the slice of forms written at its call site,
-;;;; and answers one form. That is where variadics come from in a language with
-;;;; no &rest: (len args) is how many were written.
+;;;; Every macro below is written [& args] and picks its arguments apart by
+;;;; hand, which is what a macro looked like before parameter lists: & binds
+;;;; the whole call as a slice of forms, and (len args) is how many were
+;;;; written. macro-params.flan is the other spelling of the same grammar —
+;;;; named parameters, [ ] patterns, & only for the tail — and the two files
+;;;; are kept apart on purpose, so that each is a whole program in one style.
 
 ;; The simplest one there is: two forms, in order. It proves the call site's
 ;; arguments arrive as forms and come back as code.