READ and "illegal" characters

["Steve Bacher (Batchman)" <SEB1525@draper.com>]

Taking the description of the CL reader at face value, I infer that an
"illegal" character may occur in a symbol name if it is preceded by a
backslash ("single escape"), but not if it occurs inside a pair of
vertical bars ("multiple escape").  This seems strange.  Is it merely
an oversight, or is it intentional?
  
This is a potentially significant problem, because it mandates that the
printer must slashify "illegal" characters by preceding each one
individually with a backslash rather than being able to just surround
the entire name with vertical bars.  For some implementations (i.e. mine),
it is easier to embar the entire name, once it is determined that funny
characters are present somewhere in the name.
  
Is it intended that all characters not listed in the table as consituent,
macro, etc. are "illegal"?  Or might an implementation be able to treat
them all as constituent characters?