I think you should read this: http://en.wikipedia.org/wiki/Fragment_identifier#Examples
So the de-facto standard format for multiple parameters should be #param1=value1¶m2=value2
You can see this way is used by Media Fragments URI 1.0 and by PDF documents. There seems to be no standard for HTML resources though as you can parse the fragment in JavaScript in any way you like. But I'd use the same format as it looks more natural being similar to the query string format. If the browser cannot find any element with id/name equal to your hash fragment, it will navigate to the beginning of the document by default.
Also browsers will consider the complete hash fragment as a possible id/name. So they will look for id/name equal to param1=value1¶m2=value2
but not just param1
.