Proposed Wording Change to the Error Terminology

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: 18 Mar 88  1746 PST
    From: Dick Gabriel <RPG@SAIL.Stanford.EDU>

    \item{\bull} No implementation is allowed to extend the semantics of the
    \OS\ to this situation; the effects of the situation may be described
    or specified by the implementors, but the effects may not be described
    as an extension to the \OS\.

I must confess that I cannot figure out what this means.  Do you mean simply
that the word "extension" may not appear in the implementation's description?
The previous text "the effects of the situation may be harmless, but they
must remain undefined" seemed a little clearer to me, although still pretty
obscure.  With both wordings, I would find it very difficult to decide whether
an implementation did or did not conform to the specification in this respect,
unless the test is simply whether the word "extension" appears in the
documentation (and the documentation is in English).

To try to help clarify this, let me offer two proposed rewordings to choose from:

(1) the effects of the situation may be described or specified by the
implementors, but the description must warn that portable programs cannot
depend on this behavior.

(2) the effects of the situation may be described or specified by the
implementors, but the description must warn that no properly written
program, portable or not, should depend on this behavior.