I see what you mean. My comment wasn't clear. What I had in mind was P4
documents that haven't yet been converted to P5. In that context, all
existing P4 documents will be broken by P5, regardless of the outcome of
this rend proposal. In that sense, the problem of breaking existing
documents is not the main argument against this particular proposal. The
many other objections that I and others have raised are more serious, in
Martin Holmes wrote:
> Greg Murray wrote:
>> Breaking existing documents is certainly not the main disadvantage.
>> All documents break from P4 to P5, so that's a minor consideration.
> I respectfully disagree with this. When you plan to port a project from
> P4 to P5, you allow for the time it's going to take you to refactor the
> code. When you start a project with P5 (after many assurances over a
> long period of time that P5 is pretty much ready, and should be used in
> preference to P4), you don't usually plan for refactoring code. I think
> at this stage with P5, it's fine to add new elements or attributes, or
> make other changes that don't break existing code, but it's a serious
> step to make a change that requires this much work. If the existing rend
> attribute were left in place, or an alternative attribute with the same
> content model were provided instead, then a simple search-and-replace
> would solve the problem, but the change as proposed will involve some
> serious work on many projects.
> P5 is not perfect, and it never will be, but at some point it has to be
> _finished_, IMHO, so we all know where we are. Then we can look ahead to
> P6 with a fresh slate.