Re: mid and cid URLs

Al Gilman (asg@severn.wash.inmet.com)
Tue, 21 Nov 1995 21:06:54 -0500 (EST)


From: asg@severn.wash.inmet.com (Al Gilman)
Message-Id: <9511220206.AA08218@severn.wash.inmet.com>
Subject: Re: mid and cid URLs
To: masinter@parc.xerox.com (Larry Masinter)
Date: Tue, 21 Nov 1995 21:06:54 -0500 (EST)
Cc: asg@severn.wash.inmet.com, elevinso@Accurate.COM, ietf-types@cs.utk.edu,
In-Reply-To: <95Nov21.141741pst.2733@golden.parc.xerox.com> 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:
  
       news:<newsgroup-name>
       news:<message-id>
  
     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:

mid://rtfm.mit.edu/internet-services/access-via-email_814453424;
  newsgroups="alt.internet.services,alt.online-service,
  alt.bbs.internet,alt.answers,comp.mail.misc,comp.answers,
  news.newusers.questions,news.answers ";
  Location="ftp://rtfm.mit.edu/pub/usenet
  /internet-services/access-via-email,
  mailto:listserv@ubvm.cc.buffalo.edu/" GET INTERNET
  BY-EMAIL NETTRAIN F=MAIL "

MID: //rtfm.mit.edu/news-answers%2Fguidelines_812205939 ;
  Newsgroups=" news.answers,alt.answers,comp.answers,
  de.answers,humanities.answers
  misc.answers,rec.answers,sci.answers,soc.answers,talk.answers";
  Location="ftp://rtfm.mit.edu/pub/usenet/news.answers
  /news-answers/guidelines,
  mailto:mail-server@rtfm.mit.edu/"send
  usenet/news.answers/news-answers/guidelines"

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.