Re: Yanking text properties

[Richard Stallman]

    * The current default is that all major modes allow all special
      properties to be inserted.  If we change this default, all code that
      use special properties will break.  One way to avoid this would be
      to say "if the major mode hasn't told us which speciel properties to
      allow, assume all are allowed".

This would defeat the purpose of the feature, which is that if you
copy text from a special buffer with special properties, it loses
them.

There is no way of achieving that goal without some kind of
incompatibility.  We would just have to bite the bullet.
Fortunately there are not that many programs that use these
special properties yet, partly because we are still in the process
of figuring out just how they should work.