(SSTATUS SYNTAX #/| ...)

[Glenn S. Burke <GSB at MIT-ML>]

I believe that SETSYNTAX is what you want here;  it assumes that the
choices (bits only, MACRO, SPLICING) are mutually exclusive.  (sstatus
syntax ...) only hacks the syntax bits.  In obscure applications this
is actually useful (the fact that it doesn't clobber the macro/chtran
entry, that is), because you can do strange and perverse things with
something like "." so that it is still decimal point but also acts
like a special-token (implemented as a reader macro).  (I've done this.
It almost works.)