[apgwoz]

, is typically “unquote.” Clojure is the only “mainstream” Lisp that allows , as whitespace. Has meaning in CL and Scheme.

[kazinator]

Ancient LISP (caps deliberate) in fact had optional commas that were treated as whitespace. You can see this in the Lisp 1 Programmer's Manual (dated 1960).

This practice quickly disappeared though. (I don't have an exact time line about this.)

[eyelidlessness]

My mistake!

That’s what I get for not double checking… well… basically anything I think during my first cup of coffee.