Value of Content-Disposition header:

Content-Disposition: attachment; filename*0*=ISO-8859-15''euro-sign%3d%a4; filename*=ISO-8859-1''currency-sign%3d%a4

Test Description:

'attachment', specifying a filename of currency-sign= in the simple RFC2231/5987 format, and euro-sign=€ in RFC2231-with-continuations format.

A UA that supports could pick either, or ignore both because of the ambiguity.