draft schema maintenance procedures

[Ken Rossen <[e-mail]>]

Hi, all --

        here is a first pass at some procedures for maintenance
and evolution of the Internet X.500 schema.  This is for discussion
at the Friday segment of the OSI-DS WG meeting (also available by
Multicast!).  It's the result of the schema subgroup discussion
(Russ, Sri, Tim and me) between Amsterdam and now.

        I'll bring paper copies to this afternoon's segment for
those who want them.

        Enjoy!!
--
[e-mail]

______Cut here ______Cut here______Cut here______Cut here_______
          Procedures for Formalization, Evolution, and Maintenance of 
                    the Internet X.500 Directory Schema

                  for discussion at the OSI-DS WG Meeting
                   Houston, Texas, USA / 05 November 1993

                              Submitted by
                         Tim Howes <[e-mail]>
                         Ken Rossen <[e-mail]>
                    Sri Sataluri <[e-mail]>
                        Russ Wright <[e-mail]>


PURPOSE OF THIS MEMO

This memo proposes a set of procedures for reviewing, 
publicizing, and maintaining schema elements for use in 
Internet applications using OSI Directory Services (X.500).

GOALS OF THE INTERNET SCHEMA PROCEDURES

The goals embodied in the procedures documented in this memo 
are threefold:

.	To identify a repository and appropriate useful formats 
for publicizing and distributing schema elements (object 
classes and attributes) to the Internet community.

.	To facilitate broad-based experimentation with new 
applications of X.500 by publicizing experimental schema 
elements.

.	To maintain a stable production schema for the Internet, 
including definitions both for common core of elements and 
application-specific subschemas, and avoiding overlap of 
schema element functionality where possible.

COLLECTION OF SCHEMA ELEMENTS

The Internet Directory Schema will evolve from the status quo 
as represented in a forthcoming [Internet Draft | RFC] 
documenting the current "baseline" schema elements.  This 
baseline is expected to include both those object classes and 
attributes with applicability to a wide variety of 
applications (the Core Schema), and certain elements arising 
from specific applications (subschemas), some of which have 
been developed in other IETF WGs.

In general, within the IETF, the OSI-DS schema group will 
concern itself with evolving the Core schema while 
encouraging application-specific subschemas to be developed 
by experts in the respective applications. 

The schema group aims to align schema elements definitions 
where appropriate between the Internet schema and others 
within the Directory community.  The publicizing of the 
Internet schema for external consumption is one avenue for 
this, and consideration of schema elements documented in 
external sources is another.  Two such external sources are:

.	Standing documents of the North American Directory Forum

.	"F" series International Standard Profiles (ISPs) for 
use of the Directory, developed by the Regional Workshops 
(AOW, EWOS, OIW) and published in ISO 10616.

PUBLICIZING SCHEMA ELEMENTS

The schema group recognizes short-term and long-term 
mechanisms for distributing definitions of Internet schema 
elements.  All three mechanisms involve the use of the 
InterNIC Directory and Database Services as a repository:

.	Short-term:	Element definitions will be made 
available for anonymous FTP from the InterNIC in 
ftp://ds.internic.net/pub/src/x500/schema, and via Gopher.  
The FTP archive will include ASN.1 definitions accompanied by 
text describing the semantics and use of the object class or 
attribute.  In addition, native formats for widely deployed 
X.500 implementations, particularly the QUIPU OID Table 
format, will be included where practical.

.	Long-term:	When 1993 schema publication extensions 
to the Directory standard are implemented widely in the 
Internet, these facilities will be used to distribute element 
definitions from the InterNIC DSA.  If slow progress of 
deployment of schema publication extensions impedes this 
transition, consideration will be given to defining a 1988-
compatible directory schema for interim publication of schema 
elements.  In this case, migration path to the 1993 format 
for schema publication operational attributes will be a 
priority.

In addition to on-line publicizing of schema elements, an 
informational RFC documenting the Internet schema will be 
issued on a six-month update cycle.  This RFC will reflect 
the state of the InterNIC schema repository at the time of 
publication.

Subschemas defined by other IETF WGs or external groups in 
the Directory community but accepted by the schema group as 
stable will not be reproduced in the regularly updated schema 
RFC.  Rather, the schema RFC will contain pointers to 
documents which include the definitions.

Wherever possible, external groups will be encouraged to 
submit documents containing their subschemas for publication 
as RFCs, in order to allow interested parties to derive the 
Internet schema entirely from a reading of the X.500 standard 
and selected RFCs.

PROCEDURES FOR EXPANDING THE INTERNET SCHEMA

The schema group will make available a template for 
submission of schema elements for publicizing and 
consideration.  The template, to be defined in a later 
edition of this document, will request a definition for the 
syntax of the object class or attribute, sufficient details 
on the schema elements including information about the 
submitter, date of submission, mailing-list where discussion 
is being held, status of the schema segment, etc.  The 
template will be constructed in such a way that filling it 
out yields an ASN.1 definition for the elements.

The completed template will be submitted by e-mail to the 
alias "[e-mail]".net".

Advancement of an experimental schema element to production 
status will follow a period of experimentation, acceptance by 
the schema group. In particular, authors who submit new 
schema elements (initially assigned experimental 
classification) will be expected to make a good faith effort 
to progress the schema using appropriate working-groups and 
other standards procedures towards an Internet standard. 
Results from the period of experimentation, schema group and 
WG consensus will be the basis for decisions on advancement 
of candidate subschemas.

If it becomes apparent that there is no active 
experimentation with an experimental status schema element 
and/or no efforts to progress them as Internet standards, the 
schema elements may be retired after appropriate 
notification.

In some circumstances, more than one subschema aimed at 
addressing the requirements of the same application may be 
developed.  The schema group will accept and publicize such 
overlapping subschemas as experimental.  However, only one 
competing schema proposal for an application will be advanced 
by the schema group to production status.  As with decisions 
on advancement to production status, results from the period 
of experimentation, schema group and WG consensus will be the 
basis for identifying the preferred among competing 
subschemas.

OBJECT IDENTIFIERS

The schema group does not aim to align all Internet schema 
elements under a single OID arc.  It is appropriate for other 
groups already having registered attributes and object 
classes under their own respective OID arcs to retain 
ownership of those definitions, and advancement of schema 
elements from experimental to production status does not 
imply a change of OID.  The schema group will advance the 
registration process under an Internet arc for elements 
defined by external groups not wishing to maintain OIDs in 
the long term.