Re: mid and cid URLs

Al Gilman (
Tue, 21 Nov 1995 21:06:54 -0500 (EST)

From: (Al Gilman)
Message-Id: <>
Subject: Re: mid and cid URLs
To: (Larry Masinter)
Date: Tue, 21 Nov 1995 21:06:54 -0500 (EST)
Cc:, elevinso@Accurate.COM,,
In-Reply-To: <> from "Larry Masinter" at Nov 21, 95 02:17:25 pm

To follow up on what Larry Masinter said ...
  > 2. A more URL-traditional syntax would be something like
  but news: URLs are already in the form suggested for mid and cid.
  From RFC 1738:
     A news URL takes one of two forms:
     A <newsgroup-name> is a period-delimited hierarchical name, such as
     "comp.infosystems.www.misc". A <message-id> corresponds to the
     Message-ID of section 2.1.5 of RFC 1036, without the enclosing "<"
     and ">"; it takes the form <unique>@<full_domain_name>.  A message
     identifier may be distinguished from a news group name by the
     presence of the commercial at "@" character. No additional characters
     are reserved within the components of a news URL.
  'news:' and 'mid:' (and 'cid:') should have the same syntax. In fact,
  the only difference between a 'news:' and 'mid:' URL is that 
  'news:' has an implicit context of 'your netnews' while 'mid:' has the
  context of 'your mail'.
Good.  I can take the path-to-host in either order -- I don't really care.
But you have to understand that a MID URL is a misnomer and I am suggesting
a MID URI which is more of a URN than a URL.

To explain this better, let me suggest the following representative
"dream cites" for two of my favorite FAQs:

  news.newusers.questions,news.answers ";
  /internet-services/access-via-email," GET INTERNET

MID: // ;
  Newsgroups=" news.answers,alt.answers,comp.answers,

Both of these are using Message-ID as the anchor for a resource
name that expands to give a search list of how to retrieve it.

This continues the pattern of mapping RFC 822 headers to URI parameters.
See my note about how mailserver: should be a straightforward
application of mailto: (which use has been assumed above).

News: is an URL because it does imply "via your local news-server"

These MIDs are not URLs because they identify one content which is the
same regardless of which/what retrieval method is applied.