[rfc-i] references vs front matter

[Frank Ellermann]

Paul Hoffman wrote:

>> For xml2rfc that could give you an unused reference error.

> Just for the record: that is irrelevant to the question of
> what the RFC should look like.

It was only a plauible example how "unnecessary" references
can be found.  Not finding them is sub-optimal, last year I
stumbled over an RFC with a reference to MD5.  Because MD5
interests me I read it, and MD5 was nowhere used.  After
some digging it was clear that the RFC was based on a draft,
-09, and MD5 was removed after draft -05 (or similar).  I've
submitted that as an "erratum" (editorial: unused reference).

 Frank