Comment 2 for bug 685346

Well, http://www.lispworks.com/documentation/HyperSpec/Body/v_rd_sup.htm says:

> This variable is intended primarily to support the operation of the read-time conditional notations #+ and #-. It is important for
> the reader macros which implement these notations to be able to skip over the printed representation of an expression despite
> the possibility that the syntax of the skipped expression may not be entirely valid for the current implementation, since #+ and #-
> exist in order to allow the same program to be shared among several Lisp implementations (including dialects other than
> Common Lisp) despite small incompatibilities of syntax.

How to interpret "small incompatibilities of syntax" is an arguable issue, I do agree.

However, my general impression is that the current behavior is somewhat undesirable.