Value of Content-Disposition header:

Content-Disposition: attachment; name="foo-%41.html"

Test Description:

'attachment', specifying a name parameter of foo-%41.html. (this test was added to observe the behavior of the (unspecified) treatment of "name" as synonym for "filename"; see Ned Freed's summary where this comes from in MIME messages)

Should be treated as extension parameter, therefore almost any behavior is acceptable.