Parsers should throw this exception when they encounter
a file format that they do not support. This should only happen
when we're not able to differentiate versions by the mime. For example,
At the time of this writing, "application/wordperfect" covers all versions
of the wordperfect format; however, the parser only handles 6.x.
Whenever possible/convenient, it is better to distinguish file formats by mime
so that unsupported formats will be handled by the
EmptyParser.
However, if we can't differentiate by mime or we need to rely on the parser
to distinguish the versions (in the case that magic can't distinguish),
this exception should be thrown.