Is there any way to specify a suggested filename when using data: URI?

Question

If for example you follow the link:

data:application/octet-stream;base64,SGVsbG8=

The browser will prompt you to download a file consisting of t

Answer 1

No.

The entire purpose is that it's a datastream, not a file. The data source should not have any knowledge of the user agent handling it as a file... and it doesn't.