[input encodings]
> On the other hand using different encodings for a language within one
> document is somewhat perverse.

unusual, maybe, but not perverse.  a regular requirement is the
ability to create documents whose sections come from multiple sources
(not something it's easy to support, mind you...).  if one's original
authors are writing in polish (or russian) -- indeed almost any language
other than english, given the multitudinous national variants of iso
646 that still hang on in backwaters -- then one may expect

> So it would be reasonable to have per
> document defaults.

i would agree, but i wouldn't want to lose the ability to use other
than the default.  which rather negates the impact of the `default'