Internet Architecture Board (IAB)                              J. Levine
Request for Comments: 7669                          Taughannock Networks
Category: Informational                                     October 2015
ISSN: 2070-1721


              Assigning Digital Object Identifiers to RFCs

Abstract

   This document describes the way that Digital Object Identifiers
   (DOIs) are assigned to past and future RFCs.  The DOI is a widely
   used system that assigns unique identifiers to digital documents that
   can be queried and managed in a consistent fashion.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Architecture Board (IAB)
   and represents information that the IAB has deemed valuable to
   provide for permanent record.  It represents the consensus of the
   Internet Architecture Board (IAB).  Documents approved for
   publication by the IAB are not a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7669.

Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   (http://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Structure and Resolution of DOIs  . . . . . . . . . . . . . .   3
   3.  DOIs for RFCs . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  The Process of Assigning DOIs . . . . . . . . . . . . . . . .   4
     4.1.  Getting a DOI Prefix  . . . . . . . . . . . . . . . . . .   4
     4.2.  Retroactively Assigning DOIs  . . . . . . . . . . . . . .   5
     4.3.  Assigning DOIs to New RFCs  . . . . . . . . . . . . . . .   5
     4.4.  Use of DOIs in RFCs . . . . . . . . . . . . . . . . . . .   5
     4.5.  Possible Future Work  . . . . . . . . . . . . . . . . . .   6
   5.  Internationalization  . . . . . . . . . . . . . . . . . . . .   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   7.  Informative References  . . . . . . . . . . . . . . . . . . .   6
   IAB Members at the Time of Approval . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   The Digital Object Identifier (DOI) system assigns unique identifiers
   to digital documents that can be queried and managed in a consistent
   fashion.  The structure of DOIs is defined by ISO 26324:2012
   [ISO-DOI] and is implemented by a group of registration agencies
   coordinated by the International DOI Foundation.

   Each DOI is associated with bibliographic metadata about the object,
   including one or more URIs where the object can be found.  The
   metadata is stored in a public database with entries retrieved via
   HTTP.

   DOIs are widely used by publishers and consumers of technical
   journals and other technical material published online.

   Page 15 of [CITABILITY] indicates that (note that citations have been
   omitted):

      Typical web addresses are unreliable for locating online
      resources, because they can move, change or disappear entirely.
      But persistent identifiers are fixed, with an infrastructure that
      allows for the location of the item to be updated.  The result is
      that the identifier can provide persistent access to the data.
      DataCite provides such a service, and DOIs (used by DataCite) were
      by far the identifier most commonly mentioned by interviewees,
      closely followed by Handles (on which the DOI system is built).
      There was a keen preference for DOIs from interviewees because
      this is a system already used and understood by publishers for
      traditional publications and so the barrier to uptake would
      presumably be lower than for an entirely novel system.

   Some scholarly publishers accept DOIs as references in published
   documents, and some versions of BibTeX can automatically retrieve the
   bibliographic data for a DOI and format it.  DOIs may have other
   advantages, such as making it easier to find the free online versions
   of RFCs rather than paywalled copies when following references or
   using some document indexes.

   The benefits of DOIs apply equally to documents from all of the RFC
   submission streams, so all RFCs are assigned DOIs.

2.  Structure and Resolution of DOIs

   DOIs are an application of the Handle System defined by RFCs
   [RFC3650], [RFC3651], and [RFC3652].  For example, a DOI for an RFC
   might be as follows:

      10.17487/rfc1149

   The first part of a DOI is the number 10, which means a DOI within
   the Handle System, followed by a dot and a unique number assigned to
   a publisher, in this case 17487.  This part is the DOI prefix.
   Following that is a slash and a text string assigned by the
   publisher, called the DOI suffix.

   DOIs are treated as opaque identifiers.  The DOI suffixes assigned to
   RFCs are currently based on the "doc-id" field of the RFC index in
   XML (rfc-index.xml), but the suffix of future RFCs might be based on
   something else if circumstances change.  Hence, the reliable way to
   find the DOI for an RFC is not to guess, but to look it up in the RFC
   index or on the RFC Editor website <https://www.rfc-editor.org/>.
   RFC references created from entries in the usual bibxml libraries
   will have DOIs included automatically.

   Although the Handle System has its own protocol described in
   [RFC3652], the usual way to look up a DOI is to use web lookup.  A
   proposed "doi:" URN was never widely implemented, so the standard way
   to look up a DOI is to use the public HTTP proxy at
   <https://dx.doi.org>.  The example DOI above could be looked up at:

      https://dx.doi.org/10.17487/rfc1149

   Whenever a publisher assigns a DOI, it provides the bibliographic
   metadata for the object (henceforth called a document, since that is
   what they are in this context) to its registration agency that then
   makes it available to clients that look up DOIs.  The document's
   metadata is typically uploaded to the registration agency in XML
   using an HTTP-based API.  Users or publishing software can retrieve

   the metadata by fetching the DOI's URL and using standard HTTP
   content negotiation to request application/citeproc+json,
   application/rdf+xml, or other bibliographic formats.

   Publishers have considerable flexibility as to what resides at the
   URI(s) to which a DOI refers.  Sometimes it's the document itself,
   while for commercial publishers it's typically a page with the
   abstract, bibliographic information, and some way to buy the actual
   document.  Because some RFCs are in multiple formats (e.g.,
   Postscript and text), an appropriate URI is that of the RFC Editor's
   info page that has the document's abstract and links to the
   document(s) in various formats.  Hence, the URI above, when fetched
   via an HTTP request that accepts text/html, redirects to:

      https://www.rfc-editor.org/info/rfc1149

   More information on the structure and use of DOIs is in the DOI
   Handbook [DOI-HB].

3.  DOIs for RFCs

   With DOIs assigned to each RFC, it is useful to include DOI
   information in the XML bibliography as a "seriesInfo" item, so that
   rendering engines can display it if desired.  Online databases and
   indexes that include RFCs should be updated to include the DOI, e.g.,
   the ACM Digital Library.  (A practical advantage of this is that the
   DOI would link directly to the RFC Editor, rather than perhaps to a
   copy of an RFC behind a paywall.)

   Since RFCs are immutable, existing RFCs still don't mention their own
   DOIs within the RFCs themselves, but putting their DOIs into indexes
   would provide value.

4.  The Process of Assigning DOIs

   There are three phases to assigning DOIs to RFCs: getting a DOI
   prefix, retroactively assigning DOIs to existing documents, and
   updating the publication process to assign DOIs as new RFCs are
   published.

4.1.  Getting a DOI Prefix

   There are ten registration agencies [DOI-RA] that assign DOI
   prefixes.  Most of them serve specialized audiences or limited
   geographic areas, but there are a few that handle scholarly and
   technical materials.  All registration agencies charge for DOIs to
   defray the cost of maintaining the metadata databases.

   The RFC Editor chose CrossRef, an agency widely used by journal
   publishers.  The prices associated with CrossRef membership are on
   the order of $660.00 per year for membership, deposit fees of $0.15
   cents per document for a bulk upload of the backfile (the existing
   RFCs), and $1.00 per document to deposit them as they are published.

   The RFC Editor's DOI prefix is 10.17487.

4.2.  Retroactively Assigning DOIs

   Other than paying the deposit fees, assigning DOIs to all of the
   existing RFCs was primarily a software problem.  The RFC Production
   Center's internal database was updated to include a DOI field for
   each RFC, the schema for rfc-index.xml was updated to include a DOI
   field, and the scripts that create the XML and text indexes were
   updated to include the DOI for each RFC.  A specialized DOI
   submission script extracted the metadata for all of the RFCs from the
   XML index and submitted it to the registration agency using the
   agency's online API.

4.3.  Assigning DOIs to New RFCs

   As RFCs are published, the publication software assigns a DOI to each
   new RFC.  The submission script extracts the metadata for new RFCs
   from the XML index and submits the information for new RFCs to the
   registration agency.

4.4.  Use of DOIs in RFCs

   The DOI agency requests that documents that are assigned DOIs in turn
   include DOIs when possible when referring to other organizations'
   documents.  DOIs can be listed using the existing seriesInfo field in
   the xml2rfc reference entity, and authors are requested provide DOIs
   for non-RFC documents when possible.  The RFC Production Center might
   add missing DOIs when it's easy to do so, e.g., when the same
   reference with a DOI has appeared in a prior RFC, or a quick online
   search finds the DOI.  Where the citation libraries include DOIs, the
   output (references created from those citation libraries) will
   include DOIs.

   The RFC Style Guide [RFC-STYLE] has been updated to describe the
   rules for including DOIs in the References sections of RFCs.

4.5.  Possible Future Work

   Since it is usually possible to retrieve the bibliographic
   information for a document from its DOI (as BibTeX can do, described
   above), it might also be worth adding this feature to xml2rfc, so a
   reference with only a DOI could be automatically fetched and
   expanded.

5.  Internationalization

   Adding DOIs presents no new internationalization issues.

   Since DOIs are opaque, the characters used in any particular DOI are
   unimportant beyond ensuring that they can be represented where
   needed.  The Handle System says they are UTF-8-encoded Unicode, but
   in practice all DOIs appear to use only printable ASCII characters.
   The metadata for each RFC is uploaded as UTF-8-encoded XML.

6.  Security Considerations

   The DOI system adds a new way to locate RFCs and a bibliographic
   database containing a description of each RFC.  The existing
   locations and bibliographic info are essentially unchanged, so there
   is no new dependency on the DOI system.

   Were CrossRef or the DOI database to suffer a security breach, it is
   hypothetically possible that users would be directed to locations
   other than the RFC Editor's web site or would retrieve incorrect
   bibliographic data, but the actual RFCs would remain intact.

7.  Informative References

   [CITABILITY]
              Kotarski, R., Reilly, S., Schrimpf, S., Smit, E., and K.
              Walshe, "Report on best practices for citability of data
              and on evolving roles in scholarly communication", 2012,
              <http://www.stm-assoc.org/2012_07_10_STM_Research_Data_
              Group_Data_Citation_and_Evolving_Roles_ODE_Report.pdf>.

   [DOI-HB]   International DOI Foundation, "DOI Handbook",
              DOI 10.1000/182, April 2012, <http://www.doi.org/hb.html>.

   [DOI-RA]   International DOI Foundation, "DOI Registration Agencies",
              July 2015,
              <http://www.doi.org/registration_agencies.html>.

   [ISO-DOI]  International Organization for Standardization (ISO), "ISO
              26324:2012 Information and documentation -- Digital object
              identifier system", June 2012,
              <http://www.iso.org/iso/catalogue_detail?csnumber=43506>.

   [RFC-STYLE]
              RFC Editor, "RFC Editor Style Guide",
              <https://www.rfc-editor.org/styleguide/>.

   [RFC3650]  Sun, S., Lannom, L., and B. Boesch, "Handle System
              Overview", RFC 3650, DOI 10.17487/RFC3650, November 2003,
              <http://www.rfc-editor.org/info/rfc3650>.

   [RFC3651]  Sun, S., Reilly, S., and L. Lannom, "Handle System
              Namespace and Service Definition", RFC 3651,
              DOI 10.17487/RFC3651, November 2003,
              <http://www.rfc-editor.org/info/rfc3651>.

   [RFC3652]  Sun, S., Reilly, S., Lannom, L., and J. Petrone, "Handle
              System Protocol (ver 2.1) Specification", RFC 3652,
              DOI 10.17487/RFC3652, November 2003,
              <http://www.rfc-editor.org/info/rfc3652>.

IAB Members at the Time of Approval

   Jari Arkko (IETF Chair)
   Mary Barnes
   Marc Blanchet
   Ralph Droms
   Ted Hardie
   Joe Hildebrand
   Russ Housley
   Erik Nordmark
   Robert Sparks
   Andrew Sullivan (IAB Chair)
   Dave Thaler
   Brian Trammell
   Suzanne Woolf

Author's Address

   John Levine
   Taughannock Networks
   PO Box 727
   Trumansburg, NY  14886

   Phone: +1 831 480 2300
   Email: standards@taugh.com
   URI:   http://jl.ly