One might say that such a thing as Baseless is impractical. Contrast that with the very practical "code-reg-less". You still for most programs are expected to have a base for your static data. Typically, parameters passed to macros within the "code space" would be static data (I know, not always).
Unless specified otherwise, references by the macro will use LA (or LAE). And it is up to you to set things up and specify things so that that LA(E) works. Peter Relson z/OS Core Technology Design
