Gnus is a wonderful program. However, when you need to attach to your
mail some files in a many different charsets it's quickly becomes tiring
to type charset=<charset name> into

| type="text/plain" filename="~/file.txt" disposition=attachment description=description

by hand. So I wrote a patch for Gnus (lisp/mml.el), with which
attachment process looks like:

| C-c C-a
| Attach file: ~/file.txt
| Content type (default text/plain): <RET>
| Charset (default nil): cp855
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| One line description: descr
| Disposition (default inline): attachment

Could you merge it into a Gnus repository?

Patch for lisp/mml.el: