The Common Lisp standard allows considerable latitude in the
details of an implementation, and each particular Common Lisp
system has some idiosyncrasies. This chapter describes ordinary
user-level features of Clozure CL, including features that may be
part of the Common Lisp standard, but which may have quirks or
details in the Clozure CL implementation that are not described by
the standard. It also describes extensions to the standard; that
is, features of Clozure CL that are not part of the Common Lisp
standard at all.